Transmission Swapping

* Automatic
* Manual

Submit corrections and additions to this information to The Olds FAQ Compiler.



Jetaway and TH-350 Swap

A TH-350 will almost fall into place instead of the Junkaway. From a length and mount standpoint it's a bolt-in. The TH350 bolts in like it grew there.

At most you might need to do some minor grinding on the crossmember. The only disadvantage is that you won't be able to drop the tranny pan to change the oil without unbolting the transmission from the crossmember and jacking it up.

Gear Selector
If you have a floor shift 67-69 car with the cable shifter, you'll need the correct bracket to hold the trans end of the cable.

The basic shifter and console were the same for both two and three speed automatics from 67-69. The differences are in the detent plate (which is a bolt-on addition to the shifter mechanism) and the shift indicator bezel (PRNDL vs PRNDSL). While it does not effect function, the 69 bezels are cosmetically different in that they say PARK/LOCK instead of just PARK. The detent plate can be removed from the shifter mechanism, but unfortunately you'll likely never find a replacement (unless it already has a shifter attached to it). As others have noted, you can grind your 2 speed detent plate to accommodate the three speed's detent locations.

Note also that I suspect the bracket on the transmission that holds the shifter cable housing (the one that the cable sheath clips to, not the one that moves with the cable) will likely be different between the Junkaway and the TH-350. I do know that the TH-350 and TH-400 brackets are different.

Your stock two-speed shifter will bolt up, but you'll likely only be able to access third and second manually; first will probably not be available (though this sometimes depends on production tolerances and how worn the shifter is).

Your two-speed shifter may or may not have enough slop to allow you to manually access all three gears. What this means is that you may not be able to get the trans into first manually. This is not a problem for normal function - the trans will work just fine in drive - just be aware of it. If you have a 68-69, you can get the three speed shift segment for your car (but if you have a column shift, you have to take the steering column apart to change it). If you have an earlier car, you can try to modify the segment with a Dremel, if you want. An alternative, of course, is an aftermarket shifter. This also solves the floor shift cable problem.

First gear will be one notch below "L". I have the console gear selector, and I can get the selector to put it into 1st gear, the L position is 2nd gear, D is drive. I've been told I should be able to adjust it, but with my stock selector and linkage, it isn't possible. There is a plate that controls where the selector is in park (it locks in a slot), reverse and what not, there simply is no room or adjustment for it go into 1st.

Your gear selector detent plate in the steering column only has two forward positions, D and L. Two choices are 1) get a column (or detent plate - but changing the whole column is probably easier) from a TH-400 car, or 2) accept the fact that you'll only be able to select D and S manually. Tranny will work fine, you just won't be able to manually select L. This is what my friend did. Of course, you can live with the Jetaway detent plate for now and change it at any time in the future.

I used the grinder to grind back the stop that the pin on your shifter bottoms out on. The stop prevents you from manually shifting into 1st gear. A file will also work. You also have to move your console back about 1/2" by drilling new mounting holes in the bracket on the floor that the console bolts up to.

Cable Linkage
The Jetaway uses a TH-400 style electrical kickdown switch while the TH-350 uses a cable. Get the carb bracket from the donor car (assuming it is also at Q-jet). The bracket from TH-350 cars have provisions for both the throttle cable and the kickdown cable. It all bolts up easily.

The TH-350 uses a detent cable (the Jetaway uses an electric downshift solenoid), or kick down cable to inform the transmission of what the trottle position is. Don't run without this! In the past I've used the mounting bracket from a 1970 350 CID to mate it to the trottle linkage. I've also fabricated my own mount bracket out of aluminum. I adjusted the detent cable so at WOT, the detent cable was fully extended. Leaving the detent cable off yields soft slooooow shifts at low rpm points (WOT 1-2nd shift at 4000rpm), no 3rd-2nd passing gear kick down, and a HOT transmisson. Basically, without the detnet cable the transmission always thinks you are shifting at 2000rpm.

The TH-350 uses a cable kickdown, the Jetaway uses an electric kickdown. For 68-69 cars you can get the accelerator pedal from a TH350 car, cut the small hole in the firewall for the cable to pass through (69s actually already have the cable punched and have a plug in place), and hook up the kickdown just like factory. If you have a 67-earlier car you'll need to fabricate a kickdown bracket and attach the cable to the carb linkage. You can probably adapt something from a mid-70s GM car originally equiped with the TH350.

Various installations of this trans have actuated the cable with the gas pedal or with a connection to the carb linkage itself. Your stock linkage is not set up to accommodate this, so you can either simply not use the kickdown (you'll need to shift from third to second manually when passing, for example), or the preferred method is to adapt a bracket from a later Olds to connect the cable to the carb's throttle lever.

It's been a while since I did the swap, but I don't remember having to do anything special with the linkage. His car also had a column shift and I'm pretty sure it bolted right up.

Driveshaft
No mods are required to the driveshaft, have the same mounting points, and use the same driveshaft yoke.

Electrical Wires
TH-350 does not use any electrical inputs, so the Jetaway wire can be eliminated, or saved if you want to later go to a TH-400.

Vacuum Lines
TH-350 uses a manifold vacuum line to the modulator.

Crossmember and Transmission Pan
On the 64-67 A-body cars, the crossmember will cover up the rear bolts on the trans pan. That's life and you'll just have to deal with it when changing trans fluid. You could try and notch the crossmember if you want to, but I've just unbolted the tranny mount bolts and jacked up the trans when changing the fluid.

After converting from the Jetaway, if you ever want to get the tranny pan off the TH-350, the cross member will need to be clearanced around the back end of the oil pan --if you notice it's already tight around the back of the Jetaway. The rear crossmember obscures the rear pan bolts, so changing the filter/gasket requires upbolting the crossmember from the tranny and the frame rails and sliding it back. If you try to do it without doing this it will take twice as long, trust me.

Other than those little things it's almost a weekend project.

Other Things to Check
Also, be sure to check the torque on the flexplate-to-crank bolts while the trans is out. Also visually inspect for cracks around these bolts. U-joints come to mind. E-brake cables need to be disconnected, so inspect at a minimum. You'll also have to get the exhaust out of the way, so look at it at the same time. May want to consider an external trans cooler if you don't already have one. Shift kit?

As I said above, this is pretty much a bolt-in. I seem to recall that the speedo cable bolted right up also. My friend pulled up at my house on a Sunday morning, and drove away with the TH-350 installation completed by late afternoon. One last piece of advice: spend the money to rent a transmission jack. This is absolutely the only way to replace an automatic from underneath. It's worth every penny. Also, get the car as high as safely possible before starting the trans R&R.

Torque Convertor
It is normal for the converter to be about half and inch from the flywheel when it is all the way on the trans input shaft. The clearance is designed to allow the trans to be installed without having the converter catch on the flexplate. In addition, it allows for manufacturing tolerances. Just pull the converter out to bolt it to the flywheel.

The 350 will not have a threaded torque convertor, so you will need a torque convertor bolt kit. It will cost you several dollars.

Other Things to Check
You may need a new speedo drive gear. Some minor bending of the tranny cooler lines may be required.

[ Thanks to Doug Ahern, Mick Gillespie, Joe Padavano, Collyn Eastham for this information ]


Jetaway and TH-400 Swap

Same as the swap to a TH-350 except for:

Gear Selector

Cable Linkage

Driveshaft

Electrical Wires

Vacuum Lines

Crossmember and Transmission Pan

Torque Convertor

Other Things to Check

[ Thanks to for this information ]


TH-200 and TH-350 Swap

Some trivia: the only reason GM put TH-200 behind the V-8 was to meet the silly government mandates which dictate required MPG based on weight. The V-8/TH-350 was too heavy so the slightly lighter TH-200 was substituted. The V-6 cars got the TH-350! Some cars got aluminum hoods and front bumper reinforcements as GM was slicing weight everywhere they could to meet these laws.

Also I counted the speedo drive/driven gears in the original trans: 19 drive/34 driven. My car has 2.14 gears and did not have FE2 originally so it probably had 195-75R14 tires when new. You need to come up with the drive gear. You can't easily get the old one out of the TH-200 since it has no removeable extension housing! You can reuse your current driven gear.

Gear Selector
Three speed to three speed: no change. You can use your existing driveshaft and shift linkage.

Cable Linkage
You do need a different kickdown assembly (as TH-200 is by cable, and TH-400 is electrical). I used, 1. GM # 1262622 downshift cable (77 Delta TH-350), and 2. throttle cable/downshift cable bracket from 1977 TH-350 Delta 88 (or any similar year TH-350 equipped Olds). The original bracket places the trans cable too far rearward. Maybe there exists a cable that would work with the original TH-200 bracket (??). But I know the stuff I used will work for you.

Driveshaft
No changes required.

Electrical Wires
Neither has electrical inputs, no none.

Vacuum Lines
TH-200C does not use a vacuum modulator. If you elect to swap in a TH-350, you will need the metal vacuum line that runs from a point near the carb to the vacuum modulator. Get the metal vacuum line from a Olds engined full size car with the TH-350. Common in '77-'79 Olds, Buick and Pontiac models.

Crossmember and Transmission Pan
TH-200 is a light duty TH-350, so it's a bolt in situation.

Torque Convertor
Same. But if the TH-200 grenaded, you don't want put more the shrapnel from one transmission to another. Get a new one or known good used one.

Other Things to Check

[ Thanks to John Pajak, Frederick Nissen for this information. ]


TH-200 and TH-400 Swap

Gear Selector
Three speed to three speed: no change. Driveshaft might need to be shortened and shift linkage might be different. Get from a donor car with a TH-375 or TH-400.

Cable Linkage
Probably different. Get the linkage from a donor TH-375 or TH-400 car.

Driveshaft
You will need a TH-400 yoke and transmount, and to shorten the driveshaft.

Electrical Wires
TH-400 requires a kickdown electrical signal. May also require TCS (throttle controlled spark) sensor input.

Vacuum Lines
TH-200C does not use a vacuum modulator, but the TH-400 needs a source of manifold vacuum to it's modulator.

Crossmember and Transmission Pan
Will require moving the crossmember rearward (should already have the mount holes if the car could have came with a TH-400), and getting a TH-400 yoke and transmount, and shortening the driveshaft. Remember, this will also require the modification of the parking brake cables.

Torque Convertor
Same. But if the TH-200 grenaded, you don't want put more the shrapnel from one transmission to another. Get a new one or known good used one.

Other Things to Check

[ Thanks to John Pajak, Frederick Nissen, for this information ]


TH-350 and TH-400 Swap

Note:This section was written in regard to swapping a TH-400 for a TH-350. Just keep this in mind when swapping a TH-350 for a TH-400.

The TH-350 to or from TH-400 is a straight forward swap, you will have to make sure you can relocate the cross member rearwards about 1 inch. Most older cars have sets of bolt holes for this. The center rubber mount is different. Relocating the crossmember can be tricky though. You CANNOT slide the crossmember back on a 1978 and up G-body. The frame extensions end where the crossmember bolts on.

The TH-350 in the 69-72 cars has the downshift cable connected to the gas pedal assy. There is square hole in the firewall close to the throttle cable which the downshift cable fits through. It's plugged with a plastic piece, just pry it out. Cut a hole by first measuring any 69-72 TH-350 Cutlass for the correct position. You also need a TH-350 gas pedal which has an extra tab welded to the metal arm to accept the end of the downshift cable

Gear Selector
The original shifter should bolt right in. TH-350's and TH-400's have the same amount of distance between shifts.

Cable Linkage
The bracket that holds the cable on the transmission end is different between the TH-400 and TH-350. The wrong bracket will mess up the cable adjustment. Second, the adjustability is at the transmission end, not the console end. The pin on the transmission's shift arm to which the cable attaches is adjustable. The pin sits in a slotted hole and is held in place with a nut. Loosen the nut, slide the pin, tighten the nut.

Driveshaft
Also, you will need to shorten the drive shaft. The dimension is ¾". A driveline shop can do this, but be aware, if the car you are putting it into has a rubber dampened drive shaft, and you are dropping in a 455 and plan on having the car hooking up when you romp on it, replace the drive shaft with a 1 piece. Many people have twisted the stock driveshaft on a Cutlass. A new shaft will probably be around $150-200 depending on where you have it made.

If replacing a short tailshaft TH350 with a short tail TH400, the driveshaft needs to be shortened 3/4".

You also will need a TH-400 front YOKE to replace your TH-350 front yoke. It's larger on the TH-400.

If your drive shaft has outside lock rings, as most TH-350 shafts do, and your new TH-400 yoke has inside locks, Spicer does make a conversion u-joint. It goes from the TH-400 (3R series) to TH-350 (1310 Spicer series) parts number 5-3022X (about $20.00).

The rear U-joints are the same, and the both yokes use the same u-joint. The 2-speed automatics from 68 and 69 found in Cutlasses also downshift electrically. You can use the switch assy and gas pedal from these cars to convert TH-350 cars to TH-400.

Also, the TH-400 yokes are easy to come by! Just get one from a full size Olds, etc. BUT BE CAREFUL! Yokes from a long shaft TH-400 (big car stuff) have a weep hole about 1/16" diameter in the back that must be plugged when utilizing a short shaft transmission. Otherwise you will have a strange leak when parked uphill! The U joint sizes matched up fine.

Electrical Wires

The TH-350 uses a kickdown cable, whereas kickdown on the TH-400 is electronic. The TH-400's switch is in the transmission and the accuator is connected to the gas pedal inside the car.

Vacuum Lines
Both use manifold vacuum for their modulators, so no change here.

Crossmember and Transmission Pan

The TH-350 to TH-400 swap will require moving the crossmember rearward (should already have the mount holes if the car could have came with a TH-400). Remember, this will also require the modification of the parking brake cables.

Also keep in mind that the crossmemeber is mounted 'crooked' in the 1978 and up G-body car, and not straight across. When I first put a TH-400 in my 79, I cut the extension off the front part of the crossmember and welded it on the back. I also had to extend back the mount of the trans, but it worked.

Torque Convertor
Both TH-350 and TH-400 use the same torque converter. If you bought a high stall converter for one, you can drop it into the other with no modifications.

Other Things to Check
The transmission cooler lines are the same shape, but longer on the TH-400.

The TH-350 and TH-400 use different yokes, one is fine and the other coarse (TH-400 is larger in size).

[ Thanks to John Pajak, Tom Millard, Joe Padavano, others for this information ]


TH-200-4R to TH-350 Swap

The swap from a TH-350 to a 2004R is a basic bolt-in.

Gear Selector

Cable Linkage

Driveshaft
Driveshaft and yoke remain the same.

Electrical Wires
There are lockup TH-350's that use the same connector as the TH-200-4R. Otherwise get the four wire square connector TH-200-4R harness from a donor car.

Vacuum Lines

Crossmember and Transmission Pan

Torque Convertor

Other Things to Check

[ Thanks to Stephen Hoover, Peter Landowski for this information ]


TH-200-4R to TH-400 Swap

A TH-200-4R's mount is in the same place as a TH-400's and it will use a stock TH-350 driveshaft. So here's my point: Some late model G-bodies came with a TH-200-4R, so this crossmember should bolt in the factory locations and mount up to a TH-400. Therefore all you would have to do is aquire a TH-200-4R crossmember, set the proper pinion angle, and shorten the driveshaft. Or you could use a dual hump cross member like I did.

Gear Selector

Cable Linkage

Driveshaft
Will need to be shortened.

Electrical Wires

Vacuum Lines

Crossmember and Transmission Pan

Torque Convertor

Other Things to Check

[ Thanks to Tom Millard for this information ]


Overdrive Transmissions

TH-200-4R versus TH-700-R4 - Which one should I use behind an Olds
Most people believe that the TH-700-R4 is better tranny than the TH-200-4R. According to the March 1995 Hot Rod Article "The Great Debate - TH-700-R4 vs. TH-200-4R - Which is the Better Overdrive", "both can handle 600 lbs-ft of torque and around 700 hp." Therefore, all you have to do is pick the correct one for your Olds. TH-200-4R's have either a BOP bell housing or a universal bell housing (BOP & Chevy). This makes it a direct bolt in for your Olds.

TransmissionOverall Rear Trans
Length Mount Position
TH-350 27" 19.5"
TH-400 28" 26.25"
TH-200-4R 27" 26"
TH-700-R4 30" 21.25"

The TH-200-4R is the same length as a TH-350 and uses the same drive shaft, but has the mount for the cross member in the same location as a TH-400. As for the TH-700-4R, it only has a Chevy bell housing [there is a rumor that some BOP bell housings exist] so an adapter plate will have to be used. It is also longer than a 400 by 2", so a custom length drive shaft will have to be made as well as the crossmember being relocated. Here is a chart which relates the lengths of the common tranny's to their tranny mount locations.


TH-200-4R versus TH-700-R4 Gear Ratios
One important thing to look at while choosing an overdrive for your Olds is the gear ratios they have. The TH-700-R4 has a huge jump from 1st gear to 2nd gear, which will hurt acceleration. The car will really launch in 1st gear but puke when it hits 2nd. I am not saying that you will be dissapointed with a TH-700-R4, but if you drag race the car at all, the the gear ratios should be something to consider. As for the TH-200-4R, the gear jumps are more evenly spaced out, and it has a better overdrive ratio. See the chart near the top of this section for common transmission gear ratios.

Figure out the resulting cruise rpm with a four speed automatic: trans 4th gear * rear gear * 168 * MPH / tire radius = RPM

You want to make sure you have enough gear in the rear end to keep the engine RPM's a little higher than your stall speed. Otherwise the transmission will slip and over heat.

Though it isn't mandatory, you might want to change the gear detent plate so that your shifter will have a position for all four gears.

[ Thanks to Tom Millard, Daren for this information ]


TH-200-4R Swap

The 200-4R is a good transmission but is very tempermental and you may need patience to get it to work correctly. And I hear it can self-destruct in a matter of miles if the throttle cable is too far out of adjustment. If the throttle cable is adjusted right and the trans isn't abused, it will last a long time.

Since your car is probably already geared for optimum mileage with a 3-speed transmission you may not gain much with the 200-4R. It is possible the rearend ratio is too high for your engine to pull the car with the trans in overdrive, and you'll end up lugging the engine. If it is any higher (numerically lower) than 2.75 I doubt your mileage will improve with the O.D., and it may actually get worse. If you installed a rearend with a lower ratio in conjunction with a 200-4R you could improve acceleration without compromising mileage.

The swap is fundamentally a "bolt-in" (nothing needs cutting, drilling, or welding). It can be performed "a la shade tree" for less than $500. A TH-200-4R will bolt up just fine, because it's the same bolt pattern and length as a TH-350 or TH-200 or TH-250. See chart above. Thankfully, older Olds' have the frame drilled for just about any tranny imagineable. It DOES however use a TH-350 driveshaft yoke. Doing the reverse, swapping a TH-350 in place of a TH-200-4R is a direct swap.

Backround
To begin, the TH-200-4R is loosely based on the TH-200 metric with the addition of an OD drum. Due to their relation to one another, the TH-200-4R has an undeserved reputation of being weak like its notorious sister the TH-200. Although the TH-200-4R will not hold up very well it its stock form, there are a few modifications that will increase its strength and dependability.

Info Resource
Most if the information I have gathered is from Mike Kurtz at PMAC in Houston, TX. Most of the guys on the TR (Turbo Regal) Internet Mail List speak highly of him, and you can get a text file of TH-200-4R questions from the Turbo Regal Web page.

Cores to Use
According to Mike, the most important thing in rebuilding a TH-200-4R is the core you use. 1986 and 1987 Turbo Regal transmission are the best cores to use while the 1985 and under Turbo Regal's, Monte SS's and 442/Hurst's are the next best. The reason the 1986 and 1987 TR transmissions are better cores is that they have a larger reverse boost valve, special governor, and a larger 2-3 intermediate servo. The 1985 and under Turbo Regal's, Monte SS's and 442's transmissions are very similiar, and use the same valve bodies (which is important), and they can be upgraded to 1986 and 1987 Turbo Regal types with parts from GM.

To determine what type of core you have or need, you have to look at the code (see listing above). This code can be found on the passenger side of the transmission near the driveshaft and is attached with one rivet. Sometimes these tags were installed backwards at the factory, so it is possible that the code is facing the wrong way. The tag is a small piece of aluminum that will be either natural and yellow or natural and blue, and will have the 2 or 3 letter code on it along with the serial number stamped on it. The serial number will also include the 2 or 3 letter code mentioned above. This code is EXTREMELY important! Most people do not know that there is a difference between these transmissions. I've had people tell me that a "TH-200-4R is a TH-200-4R", and that is wrong.

According to Mike Kurtz, he has never had any success with any other valve bodies than the ones marked with asteriks above. Although the casting numbers are the same, I am pretty sure that the bore sizes of the valves within the valve body are different. This makes a big difference in the shift quality of the transmission.

Gotchas
The biggest problems you will run into with the TH-200-4R is the rear crossmember mount, the driveshaft, and the throttle cable. The TH-200-4R crossmember mount is the same location as a TH-400.

The transmission is exactly the same length as a TH-350, and it is one inch shorter than a TH-400. If a TH-200 is shorter than a TH-200-4R then you'll need a longer driveshaft. The throttle cable on a 2004R must be located perfectly for the transmission to survive, and an adapter will probably be neccesary to mount the throttle cable. A TH-350 kickdown cable can be used in place of the TH-200-4R cable if it makes adaptation any easier, and there are universal throttle cable mount kits availible.

The torque converter lockup can be controlled with a toggle switch. The gear shifting is done completely by the valvebody in 88 and older(I think) transmissions. Another problem you could run into is the final drive ratio. If the rearend ratio is something like 2.8 or 2.5, the TH-200-4R will give you too high a final drive ratio. For instance, a 2.75 rear end ratio and a .67 overdrive in the TH-200-4R will give you a final drive ratio of 1.8425. The rearend ratio may have to be changed.

You can either hook up a simple toggle switch (I'd get fancy using a momentary pushutton to energize a relay and light an LED and tie the brake lights into the system to de-energize the relay and unlock the TCC when you use the brake), or find the wire from the computer (can't help you there), or Summit sells a kit to lock up the converter in non-computerized cars.

As it is, the benefit would be gas mileage and reduced engine wear from lower RPM's. If you swapped the rear gears out for something steeper, you could gain a bit of performance while still using the overdrive to still keep your RPM's at or below where they were with your 3-speed (in 4th gear).

[ Thanks to Tom Millard, Greg Pruett, Tom Lentz for this information ]

Parts, Upgrades to Use
Governor:
The governor in a TH-200-4R determines the WOT shift points while the location of the TV cable determines the shift points at anything under WOT. The tranny's marked with an asterisk (*) above have special governors that will shift anywhere between 4800-5000 rpms at WOT, depending upon their car model application. Stock governors on non-performance based cars shift at 3000 rpm at WOT. This is important because with the 3000 rpm type governor, the transmission will shift from 1-2-3-4 very rapidly which makes for poor acceleration at mild or light throttle.

Upgrades:
There are a few common upgrades that most reputable transmission builder installs in TH-200-4R's. These include a 10 vane pump, heat treated stator, pressure regulator valve, and a shift kit.

Pump:
To replace the stock 7 vane pump, a 10 vane pump with heat treated vanes and steel rings is used. This reduces irradic pressure readings with the addition of the extra vanes while the very brittle cast iron ring is replaced with a steel ring. (This brittle cast iron ring is a common weak point in the TH-200-4R.)

Heat Treated Stator:
If you look at the stator in a stock TH-200-4R, you will probably observe extreme wear marks on the splines. Art Carr claims that a worn stator will cause premature failure on the thrust bearing in the engine. Therefore, most aftermarket companies sell a heat treated version to replace the worn stock one. This has to be pressed into the pump, and costs around $70.

Pressure Regulator Valve:
To increase the line pressure and also reduce pressure fluctuations, the stock pressure regulator valve can be replaced with a 'performance' one. This costs around $20 and is available from Art Carr and Mike Kurtz @ PMAC. My trans kept starting off in 2nd gear as well as not shifting at WOT from 1-2. I spoke with a tech at Level Trans and he told me to replace the high pressure regulator valve and spring with stock items. I used a valve and spring from my 1986 Monte SS core and this completely solved the problems.

Shift Kits:
There are a couple of kits available on the market, but the one most of the guys on the TR list recommend is the one from Mike Kurtz. His kit is a modified Trans GO kit that works very well. I have installed it on my transmission and am very happy with it. B&M also makes a kit that works well, but a few guys have had trouble with them. As for the Trans GO kit, they strongly recommend you avoid this kit due to a missing parts, etc. One of the newer Trans Go kits has you drill the valve body itself which is bad news since you can never go back to where you started. Keep in mind that a new TR valve body from GM costs over $500 with a $250 core charge.

Overdrive Activation:
The overdrive in a 200-4R is activated by the valve body in the trans if it is an 1988 or older. The torque converter lockup is activated by computer. You could either ignore it and suffer in gas mileage or activate the lockup via a switched 12 volt source. There is also a kit availible that will lockup the converter automatically using some type of pressure sensor in the valvebody. If the car was originally availible with the overdrive then the means for automatic lockup by the car's computer may already be there. Ignoring the lockup may cause exessive heat buildup due to the torque converter slippage, and lead to premature transmission failure.

DISCLAIMER
I spent all summer playing with my TH-200-4R and spending alot of time talking to guys on the TR list as well as to other tranny builders. Sometimes these tranny's can cause grief, but really work well when the bugs are ironed out. Please keep this in mind before tackling such a project.

Results
My TH-200-4R resides in my 403 powered 1979 Cutlass. The car is equipped with 245 60 rear tires with an overall 25.75" diameter. I just installed 4.10's in the 8.5" 10 bolt and the engine tachs 2350 rpms at 70 mph in 4th gear! With 28x9 slicks, the car crosses the traps in the quarter at 5000 rpm in 3rd gear (high 13's at 97 mph).

[ Thanks to Tom Millard for this information ]


TH-700-R4 Swap (mated to a BOP engine)

Backround
There are a couple of things to keep in mind when searching for an overdrive tranny, whether it be an automatic or a standard. To mention a few, one would be gear ratios while another would be practicallity. Also, The early TH-700-R4 had a different spline count than the current ones, and suffered in quality.

As for the gear ratios, if you ever plan on racing the car (¼ mile or whatever), be leery of the TH-700-R4. Although 1st gear is extremely low, 2nd gear is much higher, which really hurts acceleration. The car will really launch in 1st gear but when it hits 2nd it will puke. As for the gear ratios for the 6 speed, I cannot quote the exact numbers, but I do know that some of the gears are very close to one another, and therefore you can skip gears with no problems.

As for praticallity, an adapter plate will have to be used for the TH-700-R4. TH-700-R4's have Chevy bolt patterns so it will have to be converted to a BOP. Rumor has it that some BOP bell housings were made. Now if you have a TIG welder, one can modify the 700 for a BOP pattern instead of the Chev pattern. The only composite cases I have seen were used with the Chevy 2.8l V-6 in the S-10 pickup/Blazer. The 2.8L had a modified FWD bolt pattern not similar to the BOP. I have a picture of this composite bolt pattern and it is definitely not a BOP/Chevy pattern.

Hot Rod did an article on a 4L80E build up, and since it is behind a 3.8 Buick V-6, it will work behind an Olds (maybe they ran an adapter plate as mentioned before). The only problem with this is that the transmission requires a computer, which is a little more than most people want to tackle, especially in older cars. Aftermarket kits are available to take care of this. The TH-4L80E is essentially a TH-400 with overdrive.

I think my 700R4 is pre-1987. I didn't know better (at the time) to request post-87. I did request that all updates be installed (my trans builder said he did install the updates along with a shift kit).

Parts, Upgrades to Use
The swap was pretty easy and only required:

  1. 700R4 Transmission (of course).
  2. Plug for TH-350 vacuum line.
  3. New kick-down (correct name?) cable.
  4. New rubber trans mount.
  5. New oil-filler tube (old one may be used with some patient bending).
  6. Mechanical speedometer cable connection adapter (later 700R4's came with electric speedometer interface).
  7. Speedometer gears (both shaft and cable).
  8. Change electric connector (provides +12V for torque converter lockup solenoid). Old one was 2-pin, new one is 4-pin.
  9. New flex plate. Only because old flex plate had cracks where it bolts to crank shaft. Look for these and replace if found. May cause torque converter to wobble and leak oil shortly after install, due to excessive oil seal wear.
  10. Relocate cross member about 1" (from original position) towards rear.

Notes:

  1. Original drive-shaft length is OK (doesn't need mod).
  2. Original oil cooler lines are OK (don't need mod).
  3. Original linkage may need changing (if you insist on shifting to 1st gear detent position), otherwise OK.

Info Resource
This site has a little info: http://www.cobweb.net/~blazer40/700R4faq.html.

Getting Down to Business
The swap was a relativley straightforward. Just a bunch of picky details to consider. I did the swap on a 350 Olds. I don't think anything changes for other motors, but ask someone more knowledgeable before you start. I did this back in '91. So keep in mind that there may be after market parts available for some of the things I made or adapted.

The biggest mental gymnastics was making an adaptor for the TV cable to my 4bl Q-jet.

  1. The flexplate will boltup (its been awhile, but I'm 99% sure on this).

  2. The adapter plate came from TCI Part # TCI #2300B or #23000 (you'll have to check with them as one number is old or outdated) their Tel # is 601-224-8972. When I did this I had to lengthen the dowel (locater) pins that mate the engine to the tranny as the plate is an 1/8" to 1/4" thick. I believe I got some 1/2" stock and made them, but a machine shop could do it to. You'll have too see what yours look like.
    * NOTE: Dick Miller Racing Tel# 901-794-2834 and/or http://www.mspmall.com/dmr/ has a 1/4" x 24" x 24" aluminum adapter plate (Part # DMR-5034 @ $159) and longer dowel (locater) pins (Part # MOR-37932 @ $9). I don't know what your application is so the hefty plate DMR plate may be over kill, but you'll need some sort of longer pins. ALSO: Dick notes that the converter must be modified (extend the snout I believe) if you use the 1/4" thick plate. I don't recall doing that using the TCI adapter plate which I believe is 1/8" thick. See what I mean by details!!

  3. The converter lock up is electric and the guy who built up the tranny installed it for me. Carl Rossler at Rossler Transmissions in Garard, Ohio at 216-530-0066. Carl's a great guy and really knows his stuff and has rebuilt and modified many transmissions for Lingenfelter.

  4. If you are running a Quadrajet you'll need to make some kind of bracket for the TV cable (as I remember Holly Part # 2045 will work but you'll have to check).

  5. Also on the Q-jet I went through some major math contortions (one of the many reasons why kids shouldn't drop out of High School) to figure out the correct ratio arm to put on the throttle plate to run the TV cable. IT'S IMPORTANT TO GET THIS PART RIGHT OTHERWISE YOU CAN FRY THE TRANNY REAL QUICK. There may be stuff on the market now that takes care of all that. But if you're stumped... get a hold of a copy of Hot Rod Magazine August '88. Page 66 has an article called the 700 Club and it gives you EVERYTHING that you need. It's also reproduced other places, but if you get desperate e-mail me your mailing address and I'll photocopy the article for you. (There also may be newer articles with more up-to-date info. If any one has a line on that please let me know.)

  6. I used a TV cable from '82-'85 Caprice Part # 25525598.

  7. Dip Stick and Tube from an '82 Caprice Part #s 14056612 and #15531900.

  8. You'll have to relocate the cross mount on the frame for the tranny several inches to rear. That just requires drilling a new set of holes and fiddling with the E-Brake cable holders.

  9. You'll need to shorten the drive shaft and as I remember it might take a different spline from the yoke. Nothing that can't be solved. Ask your tranny guy. I bought an used shaft and had somebody weld it. That way I've got the original length shaft in case for some unknown reason I go back to a 350 turbo.

  10. I used a B&M Street Stick Shifter Part # 80783 (that was in '91. Don't know if its changed) I think you have to also get the 4 speed adapter plate part # 80772. I also can't remember whether you have to get a GM cable bracket or it comes in the box. Ask when you buy. When I installed the shifter I had to make a bracket that would hold it up in the center console (I got buckets). I also made it so the shifter was angled and tipped so that its line of travel was aimed directly toward my shoulder. Very ergonomic and therefore comfortable and quick to shift.

I think that's about it. I haven't blazed new territory and there are probably other ways to work around some of the details. But this should get you thinking. The work is not real tricky... you just have to pay attention to details and go slow.

I think it would be a great winter project. Plus I think you'll really enjoy the 700. Stump pulling first gear and a cruising OD. Great combo.


TH-4L80 Swap

The best setup between the 4L60 and 4L80 is a 4L80 with GVOD will be very very strong, should give you about 0.60 final drive, but it will cost $5000. A 4L60 can be had for a bit more than $1000. "Muscle Car Transmissions" in Placentia, CA advertises a 4L80 that will go right into just about any '60s or '70s GM for $2499. Also, my recollection is that Art Carr will also sell you any sort of 4L80 that you want.

For very stout small blocks, I recommend a vac. switch to unlock the converter at even moderate throttle. Also, skip the nitrous while the lockup is engaged. They can put up with the abuse from a Grand National. With a later G-body, the trans tunnel had to be pounded on a little bit. The biggest drawback probably is the price, about $2500.

The 4L80-E only comes in electronic version - you would need a controller to run without vehicle ECM. It's been done, you can get a kit from TCI, Art Carr, or the like that includes a harness and a computer (from a diesel truck) that will control a 4L80E, dunno if they'd sell it to you without one of their transmisions. Someone who's good with electronics and can read a shcematic could get the controller and tranny, splice together a harness and get it going with some work.

I've read some Mitchell's manuals in the library and it looks do-able. There's maybe 12 wires running to the transmission and if I remember correctly the transmission has a dedicated controller. It uses a TPS sensor on the engine, and maybe MAP and engine temp sensors. The tranny has some internal sensors too, I know it has an internal pressure sensor and I think the vehicle speed sensor is internal. (I'm a little vauge because I'm working from memory, I don't have the manual in front of me.)

What's really cool about the 4L80E is that someone could set it up to shift smoothly for normal cruising and then with the flip of the switch make it bark the tires every time it changes gear. Trouble is, figuring out exactly how to do it.

The 4L80E has no provision for a mechanical speedometer, so you'd have to pick up an electric one or buy one of the custom tailshafts that are availible. Maybe a regular TH-400 tailshaft would bolt on? I've never read what the weight of one is, but a 400 with overdrive would definitly be a hoss...Probably the heaviest GM tranny there is.

You do need a controller to control several things on the transmission - from the part-throttle/wide-open-throttle shift points, to the line pressure, torque converter engagement RPM, etc. In the May 1996 issue of Car Craft they did a bit of a write-up on this in reply to a message in the Tech Talk section (page 98). What they said was that ACCEL Performance Products sells a controller called a "4L80E Transmission Controller With Harness" (part No. 75100) which works either with their Engine Management System (for EFI) or stand-alone on a carbed application. With the carbed application you need to install a TPS (throttle position sensor - bracket and switch needed are available through Art Carr Performance Transmission Products) and pick up an rpm signal (from the neg. side of the coil).

There's yet another problem you'll encounter when retrofitting one of these sleek puppies into your non-computer controlled car. The speedo. These transmissions were designed to ONLY work with an electronic speedo. So, you have two choices: convert to an electronic speedometer (apparently over $800 according to CC) or you can get an extension housing for the 4L80E from Art Carr (part No. 17925 - $395) which allows the use of conventional TH-400 speedo gears and cable. Carr also has performance 4L80E converters available.

As for bolting this Chevy-bred transmission to an Olds plant - I believe (care to jump in and save the day here, Steve??) that the transmission has what's referred to as a "two-part housing" which, if I'm not mistaken, allows you to change the bellhousing on the transmission. That would solve that problem right there.

If anybody wants more info on the tranmission you can go to http://www.gmdrivetrain.com and check out the Adobe Acrobat file they've got on the transmission (explains all the features of the trans with a cutaway diagram) or if you'd like I can scan this article and make it available on the web.

[ Thanks to Greg Pruett, Steve Ochs, Trevor Lee for this information. ]


Switch Pitch Swap

TH-400 transmissions between 1965 and 1967 used a dual stall speed torque converter known as the switch pitch torque converter. The Jetaway between 1964 and 1967 also came with the switch pitch torque converter, but had a higher stall speed. These torque converters can be interchanged (ie you can put the Jetaway S/P converter on a TH-400 and vice versa).

The switch pitch TH-400 and regular TH-400 can be interchanged as well. Going to a switch pitch and using the dual stall speed capability requires a switch pitch torque converter (sometimes discarded when s.p. TH-400 was rebuilt), and a means to activate the higher stall speed. The factory used a throttle cable mounted switch with two wires running to the transmission. When idling or at WOT, 12v were sent to the transmission solenoid which activated the higher stall speed. This function can be duplicated with a dash mounted switch.

Any TH-400 can be modified to be dual pitch, but you need several specific parts to make the modification. The torque converter is one, the pump assembly is another, the input shaft to the transmission is another, and a solenoid to operate the dual pitch selection is the last. The pump housing has to be modified to mount and plumb the hydraulics for the solenoid because you don't want to have to use all the special parts that the factory used to incorporate dual pitch. Also, the electrical connector in the case has to be changed to a two pin connector. None of this is difficult, but there is a fair amount to be done.

The dual pitch converter has a normal stall speed of about 1800 RPM, and it multiplies torque just like any other converter when in the normal mode. In the high stall speed mode, the converter stalls at about 2800 RPM and does increase the multiplication of torque. If you have a large displacement engine with a lot of low RPM torque, this works well. If you have a smaller engine, or an engine with a very long cam which doesn't start to make much torque below 3000 RPM then you will probably be disappointed with the dual pitch converter. In any event, the dual pitch converter will not provide overdrive.

[ Notice: ]Please refer to the Switch Pitch Detail section as well!

[ Thanks to Greg Pruett, Rod Rickenbach, Bob Valentine, Tom Millard, Steve Ochs, David Nye, Bob Hale for this information ]


Later Turbo Hydramatic With Early Olds Engine

The bell housing bolt pattern was different on the older engines. Dave Smith makes an trans conversion, (modified trans case) have to send your case.Price about $500.00.

[ Thanks to Tim Hammerlund for this information. ]


Column to Floor Shift

There is a brachet and a lever that is required. Usually specific to trans model.

[ Thanks to Chris Sommerville for this information. ]


Tail Shafts

Here's a couple of things to consider. Will the 2" extra tailshaft make a difference? Maybe. The angle of the trans to pinion flange is pretty critical in driveline vibrations and smooth rotation of the u-joints under any suspension deflections you encounter. Too much and you may bind the u-joints in certain conditions. However, if the tranny FITS without physical interference, the extra 2" might not make too much of a difference, but I'm NOT going out on a limb and say it will be OK.

With that said, I would find it FAR more easier, for peace of mind and for fitment, to either swap the long tail TH-400 for a short tail, or sell yours and buy a short tail. Of course, SWAPPING a tailshaft and housing isn't bad if you're rebuilding the tranny anyway, but you need the tail shaft and housing piece. You can only replace those by gutting the tranny first.

If you have the tranny rebuilt, you may consider asking the shop that performs it, if you don't do it yourself, if they can replace your tailshaft and housing with a shorter one. Most tranny shops have dead transmissions laying around, and the TH-400 tailshafts are fairly easy to find.

Another thing to consider is your speedometer if you replace the tailpiece. The speedo drive gear on the tailshaft must be compatible with your intended speedo driven gear/rear end ratio. Otherwise, you end up having to get a reducer/multiplier for it. Again, if you have the tranny at a shop, they can do this for you if it's not the correct one you need.

You will need to shorten the driveshaft accordingly. A lot of industrial driveshaft shops can fix it right up and balance it for you too.

Manual to Auto

This is the easier of the manual to auto, auto to manual scenerios.

Get a flexplate and bolts, then bolt up the trans. Run your lines to the rad (and cooler if you need to). The front yoke must be changed and I believe the driveshaft must be cut a little bit. Use a new trans mount, then hook up the shifter to it. You could probably get everything you need from the junkyard. VERY simple going this way.

Rather a big job. You want to leave the MT pedals in place? Just in case? I did that on my car. You need console brackets on the floor, a hole for the shifter cable. Seal the firewall clutch rod hole. Lots of time consuming piddly things.

Pretty straightforward if not time consuming. Toughest part was finding a place [w/o manual or illustrations] to put the clutch return spring's forward end.

[ Thanks to Chris Witt for this information. ]

Radiators
GM went easy on the radiators. What's to putting a couple of plugs in the radiator if you don't use the cooler? If it is a factory radiator, it should have came with plugs installed where the cooler lines would enter the radiator.

4 Speed to TH-400
For your 1969 442, you will need to have your driveshaft shortened, and the TH-400 uses a different yoke. Of course I am sure you are aware you need a torque converter, auto flexplate, dipstick tube, radiator with a transmission cooler or an aftermarket cooler, trans cooler lines, and a shifter also.

[ Thanks to Stephen Hoover for this information. ]


Manual Transmission Crankshaft Requirements

Olds only drilled manual transmission equipped engines for pilot bearings. In 1975, Olds began machining all engines for pilot bearings. Keep in mind that these cranks are not nodular iron like the older models, and are somewhat weaker.

This will be hard to explain. If the center of the rear of your crank has an indentation with a small shoulder about 1/4 of an inch inside you can get a pilot bearing from Mondello that drives into the rear of the crank. If the back of your crank is flat in the center you will have to have it drilled. Don't cut the input shaft. It will likely cause an out of balance situation and destroy the tranny. Or at least wear it out quickly.

The front end of the input shaft of the transmission runs in a bearing in the back side of the crank. Cutting off the tit that engages the bearing is NOT a good idea, and should not be considered an acceptable alternative! Have the crank machined for the pilot bearing.

To change from an automatic to a manual transmission, you also need a clutch, pressure plate, throw out bearing, clutch linkage, and a flywheel, and probably another starter.

You are going to have to buy a clutch and flywheel anyway. Get the Richmond Gear trans with the fine spline input. Consider the appropriate clutch from Center Force, For a flywheel get a steel SFI approved one - I personally recommend McLeod but haven't seen RAM. Check the mail order companies: PAW and Jegs for pricing.

For manual transmissions there are the Corvette and Carmaro 6-speeds. Each of those options will set you back $2000 for purchase price, and I believe they all use electronic speedometers requiring either an adapter or a electronic speedometer. I think 4000 pulses per mile. The Richmond gear is an easier fit. You need to use the yoke from a TH-400. The cheapest place to buy one new is Strang. The dealer charges something like $120, Strange charges something like $60 for an alloy one.

4 Speed

Late 70's 4 speeds
Four speeds for swapping into the late '70's and '80's Cutlass are available. People have found them in the '79 Cutlass diesels, some Cutlass Calais', Chevy Malibiu's, and Iraqi '81 V-6 Mailibu 4-doors.

In 1981 GM Canada built a special order for the Govt. of Iraq. These were a couple of thousand 1981 Malibu 4-doors. They were pretty strangely equipped: bare-bones taxi interior, V-6, 3 speed manual transmission, something like a 2.21 rear end, and A/C; desert specials. Anyway, the Iraquis cancelled the order and GM was left holding these things. They eventually decided to sell them through their dealer network at a special (i.e. cheap) price to get rid of them. Some were converted to automatics at dealerships to make them easier to sell, but most of them were sold as is.

If you ask for an "Iraqibou" in the Toronto, Calgary, or Vancouver area, they'll know what you mean if they are on the ball. Might be worth a few phone calls to some of the bigger salvage operations if the clutch linkage is that elusive. Bet some NOS parts might still be kicking around the dealer network up there too.

A-Body 4-Speed to G-Body
I have to assume that there are differences between the clutch bell crank and all associated clutch components, though is isn't outside the realm of possibility for you to adapt one. Basically, using the A-body parts, you can mock up the engine and trans in the frame (you'll want to have the front sheetmetal off for this). Use the A-body z-bar and pivot balls, and simply fabricate an anchor point for the frame end of the z-bar using 1/4" plate. The pushrod from the z-bar to the clutch fork will be the A-body part (assuming you use the A-body fork).

You'll need to fabricate a rod from the clutch pedal to the z-bar. Just make sure that the lever arm ratio on your clutch pedal is approximately the same as on the A-body pedal and you should have no problems. You can fabricate a rod from round bar stock and sphereical bearing rod ends (check Street Rodder magazine for vendors).

[ Thanks to Joe Padavano for this information. ]

Clutch Actuation Assembly Conversion
As for the hydraulic clutch setup, I use one on my race car from Coleman Machine, it's set to actuate a modified Powerglide's second control arm (comes out of where the shifter arm is) to bypass fluid pressure, like pushing in a clutch. Lots of racers around here use them this way. The slave cylinder is one that pulls the arm, so it can set behind the arm (or clutch arm, if you're using a real manual) getting it out of that cramped area right by the starter. There are also hydraulic throwout bearings that eliminate the need for anything outside the bellhousing altogether.

[ Thanks to Ken Snyder for this information. ]

5 Speed

Richmond 5 Speed
The Richmond gear 5 speed would be an exellent swap, but if I remember correctly, it's not an overdrive transmission. I think 5th is 1:1.

This conversion is very easy. You will have to replace your clutch plate with a 26 spline unit move the cross member back and drill 4 new holes (no big deal) and change the yoke on the driveshaft and have it shortened about 1 inch. Make sure you use the shifter that Richmond gear recommeneds (can't remember brand) It has more adjustment than the Hurst unit available. It should work with the factory console.

T-5
A T-5 trans will bolt up to your Olds engine if you change the bellhousing, I think you'll need some other little parts too, but I'm not sure.

[ Thanks to Jim Chermack, Edwin Burger for this information. ]

6 Speed

As for the 6 speed, aquiring the correct bell housing/clutch/hydraulic clutch setup might create some problems. I'm sure parts can be fabricated, but you might run into some difficulty.

The ZF was actually the six speed used in C4 Corvetts, and thats why he used that Corvette bellhousing, etc. ZFs, when you can find them are expensive, and probibly not the best choice on the market anymore for doing a swap. They are not as strong as other trannys, and I've heard they are really expensive to fix, and are difficult to adapt because unlike most cars, they use that pull setup on the clutch, rather than the push setup found on most cars to engage/disengage the clutch.

Richmond 6 Speed
Richmond does have a 6 speed, that has a 1:1 5th, and an overdrive 6th, though.

This conversion is very easy. You will have to replace your clutch plate with a 26 spline unit move the cross member back and drill 4 new holes (no big deal) and change the yoke on the driveshaft and have it shortened about 1 inch. Make sure you use the shifter that Richmond gear recommeneds (can't remember brand) It has more adjustment than the Hurst unit available. It should work with the factory console.

T-56
Another good candidate would be Borg-Warners T-56 six speed, the one found in the Viper, G4 Camaros, and the new Corvette. A very heavy duty trans! Fourth gear is the 1:1 just like most other trannys, and the top two gears are both overdrive (.74:1 5th, and .50:1 6th for OE trannys, and .80:1 5th, .62:1 6th for the aftermarket version).

A used OE tranny would be fairly inexpensive, but unfortunatly, they come with a digital speedo setup (the T-56's in the 93 Z/28's do not have a digital setup to my knowledge. 1994+ F-bodies do though), and a Corvette style pull clutch.

The aftermarket version is pretty expensive, but it comes with a gear driven spedo, and is designed to be used in 3rd gen Camaros and Mustangs, so it uses the usual push style clutch. The aftermarket setup also comes with an adapter plate that was designed to let you bolt it right up to a T-5 bellhousing, but by re-drilling the holes, I don't see why you couldn't make it fit an Olds bellhousing, making it an almost bolt up proposition. You can also buy and adaptor to let a T-56 trans bolt up to your Olds engine. The only thing you would have to make sure of is that the input shaft is of the right length to work with the clutch.

[ Thanks to Tom Millard, Tony Waldner, Steve Ochs, Scott, Jason Labay, Edwin Burger, Jim Chermack for this information ]

M-20 to M-21

It should be a direct swap, but . . . read on.

The only difference between a M-20 and a M-21 is the gear on the input shaft and it's partner gear on the counter shaft. All of the other gears are identical. The difference in ratios is done by this initial ratio as all except 4th go through the counter shaft. 4th is a direct coupling of the input and output shafts. If you want to convert a M-20 wide ratio to a M-21, close ratio, all you need to do is swap out the input shaft and matching counter shaft, aka cluster gear, with the close ratio parts. You can also go the other direction if you wish.

All in all Muncies are fairly "swap friendly". One other thing though, most Muncies have the speedo cable on the drivers side (left) of the tail shaft. My Olds has it on the passenger (right) side. Ch*vy and Pontiac used the left side style. I don't know what Buick used. The housing can be swapped for your application.

A good souce for 4 speed parts of all make is:

Southside Auto Parts 1710 East 29th St Muncie, IN 47302 765-284-5456
[ Thanks to Dave Wyatt for this information. ]

M-20 to M-22

My '70 W30 came with a M-20 and I changed it to a M-22. The mounting surface and crank-to-input shaft was a direct bolt in (except 13 spline to 26 spline).

Next, I had to locate a "shifter mounting plate". this was NOT the same, M-22 tail shaft is longer which positioned the shifter further back, resulting in, different plate and, a shorter drive shaft. This took a while to locate.

The shifter mounting plate is not an M-20 vs M-22 distinction, but a model year distinction. I'm not sure of the exact year (I want to say 1973, but I'm not 100% sure), but the tailhousing holes were relocated. Same year M-20s and M-22s have the same shifter plates and mounting holes.

[ Thanks to Mark Cornea, Joe Padavano for this information. ]

Auto to Manual

You need pedals, z-bar, bracket to bolt z bar to frame and engine, tranny, bell housing, clutch fork, flywheel, clutch, pressure plate, throw out bearing, pilot bearing, different length drive shaft, shifter. And you need to make sure your crank is able to recieve the pilot bearing. Install is not bad but it is costly and time consuming. You just have to make DARN sure you have all the pieces before you start.

The best bet for converting is to find a complete car which is being parted out, as there are a lot of little things you will need. Here's a starter list off of the top of my head:

If you have a 69-up car with the shifter lock and you intend to retain this, you'll need all the backdrive linkage parts as well. The good news is that installing the backdrive linkage will allow you to use the factory backup light switch. Bad news is that this linkage will not fit with headers. If you're not using the backdrive linkage or have an earlier car, you'll need to get the backup light switch kit from Hurst.

If you're starting with a column shift, the following are optional to do a nice job:

I'm not sure about the driveshaft and yoke. I think the TH-350 and Muncie are the same length, however, I'm not sure. The MT drive shafts are solid, whereas the AT shafts are two-part with the rubber sleeve between them. This can work, but it isn't the correct part. I'm also not sure if the TH-350 yoke works in the Muncie, or if you need a different one.

Note that if you are running headers, many do not fit around the equalizer without major surgery to the headers. The ancient Kenne-Bell headers in my 70 W-30 do not fit well around the clutch linkage - it's a royal pain to get it adjusted properly. Mondello (?) makes a pricey hydraulic throwout bearing kit (~$400).

As for where to get the parts, the clutch linkage is the hardest. As I noted, there are a lot of little washers, bushings, and fasteners in the whole equalizer assembly, so make sure you get a complete setup.

If you plan to run a console, you'll likely need to find a factory shifter (they were all Hurst Competition Plus units) or find an aftermarket Hurst to fit. It appears that Hurst does not list a shifter for the 68-69 cars, even though the Olds parts book claims it is the same part as for the earlier cars (which Hurst _does_ sell shifters for). I suspect the Hurst catalog is just wrong. Hurst used to sell an aftermarket unit for the 70-72 cars which fit the console (I've got one), but they no longer list it. The 70-72 console requires the shifter to have a 2" offset for the stick, as the console is centerline mounted. Earlier cars had the stick closer to the driver. If you're not planning to run a console, your shifter options are much wider.

As for clutches to use, I've tried a number of aftermarket units and I find I like the Centerforce the best. I've has some that were real left leg busters, but the Centerforce has a stock force level with excellent lockup properties.

The MAIN thing is to either get a 4 speed crank installed or take yours out and get the pilot hole drilled (don't even think about leaving it in the car to do that! Probably can be done, but I wouldn't trust the accuracy.)

The pilot bearing hole in the back of the 455 crank (if original) isn't there. For some darn reason, Olds didn't think it prudent to drill the hole on all their cranks for the pilot bearing.

Most of the 455 cranks I've dealt with have a conical recess with a shoulder. Some 403's are factory drilled and tapped for the clutch linkage pivot ball. I got a pilot bearing from Mondello that converts non 4 spd cranks. But this adapter, and possibly others, might require you to shorten the input shaft. Personally, I'd be a little hesitant to whack the end off of a several hundred dollar tranny that I just bought, but the alternative is certainly a lot more work.

You also need to change the driveshaft length and yoke, get all the hardware for the pedals, pivots and such, and cut a bloody hole in the floor for your shifter. Then you'll have fun finding the "floor shift adapter" to go with your console if equipped. You might be better off getting a complete 4 speed console for it. This is exactly the same as the auto console, save for the top plate and has an extrusion sitting in a huge cutout section of the console.

Bellhousings are relatively easy to find, as all Buick, Pontiac, and Olds units are the same.

4-speed Linkage Conversion
On 1969-up cars, from the floorshifter, there is linkage going up to the steering column, because when I shift, the collar around the column turns also. This is so the ignition lock won't work in gear, nor will it start in gear.

The conversion is pretty easy. You'll need the following parts:

And, to be really correct:

If you pull up the carpet on the transmission tunnel, you should see dimples in the floor where the hole for the shifter and cable should be drilled. I think the console bracket holes may also be pre-dimpled in the tunnel as well. the console harness for the neutral start/backup light switch will plug into the existing dash harness. Simply pull the connectors off the switch on the steering column and they should plug directly into the console harness (purple is neutral start, green is backup). The console light harness will have a plug which mate with an unused plug under the dash. This dash plug will have the same color wires as the console harness (white, black, orange, and grey, if memory serves).

I don't remember if you said whether or not you already had a shifter and console or not, but 67-69 are all the same for the AT cars. The only difference, and it is a subtle one, is that the 69 console will have a shift indicator which says "PARK/LOCK", whereas the 67-68 cars only said "PARK".

One other thing to look out for is the bracket which mounts on the tranny and holds the cable. The TH-400 bracket is different from the TH-350 bracket (which was used on 69-up Cutlasses). I'm also not sure what the Jetaway bracket looks like (yes, you could get the console with the Jetaway in 67-68 - these consoles will also have shifters set up for two-speed trannys). The arm which goes on the selector shaft on the transmission will also be different in 69, due to the aforementioned backdrive linkage. This 69 arm will work on the 68, but it will have some additional tabs sticking out. Just ignore them if this is what you have.

[ Thanks to Joe Padavano for this information. ]

From Auto Trans Back to the Original 4 Speed
I'm assuming here that the engine currently in the car is the original engine, so it will have a crank already drilled for a pilot bushing. If the current engine is not the original, there is a high probability that the crank will not be drilled. Note that the fact that the pivot ball is still on the engine indicates that it is the original unit.

I assume you have the clutch pedal-to-z-bar link and the z-bar-to-clutch fork links. Since the car was originally a 4 spd, the clutch safety switch is probably still in place, though probably bypassed. You'll probably want to reconnect it.

The Muncie is the correct trans. Just be careful of the tailhousing - I seem to recall that Ch*vy units have the speedo cable coming out of the opposite side as the Olds units.

A couple of other things to consider:
Speedo cable. The MT may need a different one (or was the original one simply hooked up to the AT? I think the 4spd cables are longer)

Backdrive linkage. The backup lights are operated by a switch on the steering column (it is the same switch which also contains the neutral start switch for AT applications). Since the Feds required the trans to be locked with the steering column, both AT and MT applications used a backdrive linkage which connected to an arm at the base of the steering column. This linkage connected to the reverse arm of the 4spd and required the car to be in reverse to lock the ignition and remove the key. It also served to activate the switch on the steering column to operate the backup lights. The first question is: was this linkage reinstalled with the AT? The second question is: do you care? The backdrive linkage must be removed to install headers anyway. I've done this on my 70 W-30 and just do without the interlock. In order to operate the backup lights I simply rotate the collar on the steering column, which in turn puts the switch into contact. You can also buy a backup light switch kit from Hurst.

Driveshaft yolk. The TH350 yolk should be the same as the one on your 4spd, but check it to be sure. Driveshaft length is obviously the same.

Shifter. Are you planning to retain the console to go with the MT? Olds used the same basic console for all applications (3spd, 4spd, auto, and dual gate). In the MT applications, there is an adapter which goes on the top of the console to mate to the shifter boot. Good luck finding one if you don't already have one.

[ Thanks to Joe Padavano for this information. ]



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