Special thanks to Tim McChesney for submitting this info
Retyped VERBATIM by Bryceman
SUPER-TUNING AND BLUEPRINTING SPECIFICATIONS
FOR 1969 & 1970 OLDSMOBILE 350 AND 455 CU. IN.
ENGINES
AND "W-MACHINE" OPTIONS
Published by Oldsmobile - Spring, 1970
A. SUPER-TUNING
Super-tuning is a term that means bringing every component within the engine up to
its peak. Many times off-road operation calls for different settings and
adjustments than are proper for street use. A well tuned engine requires proper
ignition and carburetor settings, a good performing valve train and non-
restrictive air cleaner and exhaust system.
Ignition
Stock distributors on each of the W-Machines have mechanical advance curves which
parallel best spark timing. The mechanical advance curves, vacuum advance curves,
and initial timing settings on all models are selected to give best performance
with the normal carbon build-up and street equipment. For off-road use in a car
where the amount of idle and low speed operation will be held to a minimum,
higher timing settings may be used. However, precautions must be taken:
1. Disconnect vacuum advance hose at the distributor and plug the hose.
Leave the distributor vacuum connection open. This will preclude road
load detonation which must be avoided for long engine life.
2. Use super premium fuels to further avoid detonation.
3. Be conservative. Increase timing in small steps, listening for any
detonation ("knock")
The important area to watch in changing timing is the advance above 4000 RPM (with
vacuum disconnected). For off-road use, timing should be set to give 35 degrees
advance BTC above 4000 RPM. Advance beyond 35 degrees should be done in small steps
against a timer and in conjunction with changes in carburetor jetting, slight
richening until ultimate potential is realized.
To set timing accurately above 400 RPM, a new set of scribe marks will have to be
added to the balancer, since the normal timing tab stops at 15 degrees BTC. These
marks must be made on the balancer below the present mark (clockwise from the
front of the car). Timing can then be read using the 0 degree mark on the tab and
the new marks on the balancer, while revving the engine to 4000 RPM momentarily.
CAUTION: DO NOT LOOSEN THE DISTRIBUTOR HOLD DOWN BOLT AND ADJUST WHILE
REVVING THE ENGINE. MOVE THE DISTRIBUTOR A SMALL AMOUNT, TIGHTEN, AND
REV TO 4000 FOR 2-3 SECONDS.
Scribe the marks clockwise from the present mark per the following chart:
Degrees BTC 350 Engines 400 & 455 Engines
30 1 7/8 inches 1 11/15 inches
35 2 3/16 inches 1 31/32 inches
40 2 1/2 inches 2 9/32 inches
B. The production method of setting the timing may be used if the mechanical advance
curve is known (check curve on a sun machine). The following chart lists the
production distributors with settings, along with suggested settings to achieve 35
degrees BTC above 4000 RPM.
1969 --- W30: Distributor Number 1111933
- Production initial setting of 14 degrees BTC at 1250 RPM provides 27 degrees
BTC timing above 4000 RPM.
- Change to 15 degrees BTC at 500 RPM or less, or 17 degrees BTC at 800 RPM to
provide 35 degrees above 4000 RPM.
1969 --- W31: Distributor Number 1111930
- Production initial setting of 12 degrees BTC at 1000 RPM provides 30 degrees
BTC timing above 4000 RPM.
- Change to 15 degrees BTC at 800 RPM to provide 35 degrees above 4000 RPM.
1969 --- W32: Distributor Number 1111989
- Production initial setting of 14 degrees BTC at 850 RPM provides 37 degrees
BTC timing above 3000 RPM.
1970 --- W30 SMT: Distributor Number 1111977
- Production initial setting of 12 degrees BTC at 850 RPM provides 34 degrees
BTC timing above 4000 RPM.
- Change to 13 degrees BTC at 850 RPM to provide 35 degrees BTC above 4000 RPM.
1970 --- W30 AMT: Distributor Number 1111979
- Production initial setting of 10 degrees BTC at 850 RPM provides 33 degrees
BTC timing above 3000 RPM.
- Change to 12 degrees BTC at 850 RPM to provide 35 degrees BTC above 3000 RPM.
1970 --- W31: Distributor Number 1111975
- Production initial setting of 14 degrees BTC at 1100 RPM provides 30.5
degrees BTC timing above 4000 RPM.
- Change to 15 degrees BTC at 800 RPM to provide 35 degrees BTC above 4000 RPM.
1970 --- F85, 4-BBL (310 hp): Distributor Number: 1111975
- Production initial setting of 10 degrees BTC at 1100 RPM provides 26.5
degrees BTC timing above 4000 RPM.
- Change to 15 degrees BTC at 800 RPM to provide 35 degrees BTC above
4000 RPM.
1970 --- 4-4-2 (Except W30): Distributor Number 1111982
- Production initial setting of 12 degrees BTC at 1100 RPM provides 30 degrees
BTC timing above 4000 RPM.
- Change to 15 degrees BTC at 600 RPM to provide 35 degrees BTC above 4000 RPM.
The timing indicator (tab) is marked (in degrees) -4, -2, 0, 2, 4, 6, 8, 10, etc. The
top edge of the tab is 14-15 degrees BTC.
To insure against point bounce with high RPM usage, double springing of the
production point springs may be done. The best method is to use Corvette Delco points
No. 1966294. These points are good to 7000 RPM.
C. CARBURETION
Carburetors are calibrated for best full throttle as best part throttle mixtures and
street performance. The best starting point for off-road use is production
specifications. However, because of varying climactic conditions and the fact that
exhaust headers will be used and part throttle driveability need not be considered,
a number of changes may be tried.
First, production specifications are as follows:
MODEL PART # PRIMARY PRIMARY SECONDARY SECONDARY ROD
ON CASTING JET METERING ROD METERING ROD END DIAPHRAGM
1970 W30 7040251 .070 Yes AU .053
7040256 .058 No AU .053
7040258 .070 Yes AU .053
1970 W31 7040255 .057 No AU .053
1970 365hp 7040251 .070 Yes AU .053
7040257 .070 Yes AU .053
7040253 .069 Yes AT .067
1970 310hp 7040250 .070 Yes AT .067
7040253 .069 Yes AT .067
1969 W30 7029254 .075 Yes AU .053
1969 W31 7029255 .074 Yes AU .053
1969 W32 7029251 .070 Yes AU .053
Operation
Normal Driving up to 1/2 throttle is done with the primary side of the carburetor.
Fuel is controlled by the size of the primary jet and large end of the tapered primary
rod.
At full throttle, the fuel is controlled by the primary jet and small end of the primary
rod plus the addition of fuel through the secondary jet and rod.
The position of the secondary rod relative to the jet is controlled by the angle of the
secondary air valve. Therefore, the full throttle fuel rate as well as air flow is
controlled by the air valve.
Air valve position or angle is controlled by air flow pulling against the air valve
spring. Air valve wrap is the term that describes the amount of pre-load adjusted into
the spring. Earlier opening of the air valve naturally allows more air flow; but if
opened at too low a RPM, might give might give improper fuel mixtures and distribution,
resulting in a loss of low end torque or a "bog".
Production setting allow the air valve to begin opening at approximately 1500 RPM full
throttle and reach full open at approximately 3500 RPM.
The dashpot or diaphragm located at the right-front corner of the carburetor effects
the air valve as well as choke operation. It provides a smooth opening of the air
valve rather than the popping open when the secondaries are reached. It is used mostly
for less than full throttle maneuvers, but can also be a benefit for full throttle
operation, especially with the intake manifold heat crossover blocked. By delaying the
opening rate of the air valve, less spring wrap may possibly be used.
Variations of all the above should be tried; primary jets and secondary rods for fuel
mixture, and air valve wrap, with and without the dashpot for low and mid-range power
and feel.
SECONDARY METERING RODS
The following chart compares various rods with the AU:
ROD END DIA. DESCRIPTION
AU #7033658 .053 inch Stock W30, W31, 4-4-2 Automatic
AT #7033658 .067 inch Stock 4-4-2 Synchromesh and 310hp
Same below 3500 RPM as AU
4.5 percent leaner above 3500 RPM
AX #7033549 .042 inch 5 percent richer below 3500 RPM than AU
3 percent richer above 3500 RPM
AG .030 inch 3.5 percent richer below 3500 RPM than AU
5 percent richer above 3500 RPM
Production rods can be machined to a smaller diameter, but must be done only with
precision machinery. Only the small straight portion of the rods should be changed.
Remember, the distance from the bottom of the hook to the top of the straight portion
must be 2.5 inches or less.
PRIMARY METERING JETS
Full throttle fuel rate can also be altered with changes in primary metering jets.
Each .001 inch jet size change is equivalent to 1.5 percent change in full
throttle fuel mixture. Since the primary jets affect part throttle operation and
since the top of the carburetor must be removed to reach the jets, changing the
secondary rods should be done first.
Richening of the primary jets could give a more responsive off-the-line feel.
SECONDARY BLEED TUBES
The secondary bleed tubes are air bleeds into the secondary wells, which aid
secondary tip-in response in normal driving. Though they also help control the fuel
mixture, they are not an especially good tool to use. They are small brass tubes
that protrude out of the top of the carburetor beside the secondary rods. Plugging
these tubes with toothpicks will greatly enrich the mixture, approximately 10 to 20
percent, but the exact change is unpredictable and could affect distribution.
The necessary enrichment on a stocker can be easily achieved by use of available
jets and rods without using the bleed tubes. However, if a highly modified engine
is used, and further enrichment is needed, the bleed tubes do have a great effect.
PRIMARY METERING RODS
The primary metering rods should NEVER be changed. All Rochester primary rods have
the same .026 inch diameter on the small end. Changing to another rod can only
affect part throttle operation. Since the large end of the rod is a tapered surface,
which is pre-set at the factory, any change would give an unpredictable effect.
SECONDARY METERING ROD HOLDER
This rod holder is also known as a hanger, yoke, or lever. It holds and positions
the secondary metering rods in the secondary jets. Changing the height of the holder
by bending should NEVER be done. Any change would definitely be unpredictable, with
no way of returning to the baseline. Also if one side is bent more than another very
poor distribution will result.
Raising the holder raises the secondary rods during their travel. This will richen
the mixture below 3500 RPM, while not affecting the mixture above 3500 RPM.
Lowering the holder will lean the mixture below 3500 RPM and will lean the mixture
drastically above 3500 RPM. Again, the change is unpredictable.
If experimentation in this area is desired, the holder can be raised by placing
narrow shims under the holder, one in front of and one behind the mounting screw.
Better yet, a new holder can be used. The holders are letter coded A, B, C, etc.
Each letter size indicates a .005 inch change in rod height, with A being the
highest or richest, Z the lowest and leanest.
The hanger is selected at the factory to make the carburetor flow properly.
Therefore, a carburetor with a D holder is not richer than a carburetor with an
M holder.
If a particular carburetor has an N hanger the secondary rods can be raised .010
inch by using a K hanger, and lowered .010 inch by using an O hanger. You can see
that this is a very touchy area.
AIR VALVE WRAP
The air valve wrap is the amount of pre-tension applied to the air valve by the
air valve spring. The spring is located at the right end of the air valve shaft
(passenger side). An adjusting screw can be found on the right side of the
carburetor, with an allen head lock screw below. The wrap 1/2 turn or 3/4 turn
is the angle the adjusting screw is turned BEYOND the tension required to just
close the air valve with vibration.
Before adjusting or changing the air valve wrap, note and scribe a mark where
the adjusting screw is at present.
To check wrap as received:
1. Place a narrow screwdriver in the adjusting screw.
2. Loosen the lock screw.
3. Back off, by turning counter-clockwise, the adjusting screw while
"tapping" on the casting with the handle of a larger screwdriver.
Note the number of turns or part of a turn before the air valve
begins to open.
To set the wrap:
1. Loosen the lock screw and back off the adjusting screw until air
valve opens.
2. Begin closing the air valve by turning the adjusting screw
clockwise while tapping on the casting until the air valve just
barely closes.
3. Turn the adjusting screw an additional turn, 1/2, 1/4, etc.
clockwise.
4. Tighten the lock screw.
Do not use more than one turn wrap to avoid over-stressing the spring.
TEST PROCEDURE
First runs should be made with the carburetor in stock form. Subsequent runs may
be made with the following changes:
1. Disconnect the vacuum hose from the choke diaphragm and plug the hose.
Leave the spout on the diaphragm open.
2. Decrease air valve wrap in 1/4 turn steps. Make runs with connected and
disconnected. The wrap should be decreased until a loss in performance or
bog off-the-line is felt. Less wrap may be possible with the diaphragm
connected. The automatic transmission cars may need more wrap than
synchromesh.
3. After a particular wrap, with or without the diaphragm, is determined change
secondary rods and make more runs. Try going richer first, but also dont
hesitate to try a step leaner. To be sure the proper mixture has been found,
it is best to find a mixture that is too rich as well as too lean.
4. Changing wrap will affect fuel mixture in the low and mid-range engine speeds,
so additional changes in air valve wrap settings should be tried after
secondary rods have been changed.
5. Further changes in fuel mixture can be made by changing the primary jets,
plugging or restricting the secondary bleed tubes with a piece of wire, or
using a new secondary rod holder.
VALVE TRAIN
Camshafts
IMPORTANT: Production "W" car camshafts are developed on a dynamometer with cold
air induction, exhaust headers, and blocked carburetor head. Indexing these
camshafts to other than stock positions is not recommended. Additional performance
increases here are highly unlikely, since all "indexing" has already been done on
the dynamometer. Camshaft specifications are:
PACKAGE 1970 310HP AUTO TRANS 1970 365HP AUTO TRANS 1970 365HP SYNC.TRANS.
PART# 400084 400165 406768
OPENS Int 16Deg Exh 64Deg Int 24Deg Exh 74Deg Int 30Deg Exh 78Deg
CLOSES 54Deg 20Deg 81Deg 33Deg 84Deg 38Deg
OVERLAP 36 Degrees 57 Degrees 68 Degrees
DURATION Int 250Deg Exh 264Deg Int 285Deg Exh 287Deg Int 294Deg Exh 296Deg
LIFT .400 .400 .472 .472 .472 .472
PACKAGE 1970 310HP SYNC. TRANS '69 & '70 W-30
PART# 393859 402569
OPENS Int 30Deg Exh 78Deg Int 56DegBTC Exh 96DegBBC
CLOSES 76Deg 28Deg 92DegABC 52DegATC
OVERLAP 58 Degrees 108 Degrees
LIFT .472 .472 .475 .475
DURATION 286 Degrees 286 Degrees
PACKAGE '69 & '70 W31
PART# 402194
OPENS Int 40DegBTC Exh 86DegBBC
CLOSES 88DegABC 42DegATC
OVERLAP 82 Degrees
LIFT .474 .474
DURATION 308 Deg 308 Deg
VALVE SPRINGS
Production Valve springs used on "W" cars are equipped with dampers on intake and
exhaust.
Special assemblies 404729 and 398247 have special heat-set wire that will not lose
load after repeated high RPM usage.
It is not recommended to shim rocker arm stands to get near zero lash in the
hydraulic lifters. This will upset valve train geometry. It is advisable to
change springs and lifters if high RPM cannot be obtained.
B. BLUEPRINTING
For all out racing internal specs and clearances should be checked. A very
important item is piston to bore clearance.
If forged pistons are used, additional clearance is needed since forged
pistons expand more than autothermic production pistons. Use clearance
suggested by piston manufacturer.
To hone the bores for increased clearance the following is recommended:
1. Insert the piston upside down in the bore and check clearance
between the piston skirt and the bore.
2. Hone the block with a Sunnen rigid hone with a 200 grit stone to reach
the desired clearance.
The crankshaft should be ground to obtain .002 - .0025 inches connecting rod
clearance. .002 - .0025 inches main bearing clearance on 350 engines and .002
inch maximum main bearing clearance on 455 engines should be used.
For increased main bearing clearance, the following method should be used: insert
the bearings in the connecting rod or main bearing cap and torque to
specifications. Check the I.D. with a micrometer. Grind the crank for desired
clearance on a crankshaft grinder. The crank should be polished after grinding.
Connecting rod side clearance should be increased to .018 - .020 inches. To check
side clearance the rods should be installed on the crankshaft and torqued to
specifications. Install a screwdriver between the rods and gently pry apart. Be
careful not to damage the thrust face when prying apart. Insert a feeler gauge
between the rods to check clearance.
As an example, assume that this clearance is .010 inches. Then remove only one
rod and surface grind .005 inches from each side. This will total .020 inches
clearance.
Piston-to-deck clearance minimum specification is .002 inches. Naturally, all
pistons can't be made to this exacting tolerance. Pistons should be purchased
with .006 - .008 inches deck clearance. Check this clearance when assembling.
LUBRICATION
For all out performance, modifications should be made to the oiling system.
Oil pump pressure should be about 60 psi at 2000 RPM. If more pressure is
needed then a heavier oil pump bypass spring is needed or else the old one
can be shimmed.
It is also important that oil pump gears be of equal length. They should be
surface ground to equal length. The amount that they project out of the oil
pump body should be .009 inches. The oil pump body may need to be surface
ground to get this dimension. Doing the above will insure that you have a
"perfect" pump.
Main bearing oil holes should be enlarged to 5/16".
The fitting at the front of the block that squirts oil on the timing chain
should be plugged.
Toronado oil pan and pump are recommended. The Toronado pan has one more
quart capacity and a skimmer baffle.
The oil pump pick up tube should be enlarged to 5/8" I.D.
POWER TRAIN
Oldsmobile W machines are produced with excellent clutch disks, pressure
plates and flywheels; and they have good durability for street and strip.
For maximum protection in all out competition, the stock bellhousing should
be replaced with a Lakewood Industry 1/4 inch thick steel housing model P01.
There are three synchromesh transmissions available at Olds. Two ar Muncie
4-speeds and one is fully synchronized three speed. Rations are:
GEAR Muncie Close Muncie Wide Chevrolet Muncie 3-Spd.
1st 2.20 - 1 2.52 - 1 2.42 - 1
2nd 1.64 - 1 1.88 - 1 1.58 - 1
3rd 1.28 - 1 1.46 - 1 1 - 1
4th 1 - 1 1 - 1
All floor shifters are made by Hurst. They are the same basic construction
as the aftermarket Hurst competition shifter except there are no stops and
there is a sound insulation on the production shifter.
Oldsmobile started manufacturing their own differentials in 1968. The
following performance ratios are available for 1968, 1968 and 1970 for
Cutlass and 4-4-2s -- 3.42, 3.91, 4.33, 4.66, and 5.00.
The 4.33, 4.66 and 5.00 are dealer installed only. The reason for this is
cooling considerations.
Differentials with ratios of 2.56, 2.78, 3.08 and 3.23 are of different
design and the above ring and pinions will not interchange.
If you have a car with a 3.42 or numerically higher ratio then the
performance ratios will interchange.
There are four ways to modify the Turbo Hydra-matic 400 for quicker
shifting. The methods are:
A. STREET PACKAGE - Quick Shifts
1. Rework spacer plate
a. Open 2nd clutch feed orifice to .110" dia.
b. Open 3rd clutch feed orifice to .125" dia.
2. Replace 2nd clutch wave plate with flat plate P/N 8623150.
3. Replace 3rd clutch wave plate with flat plate P/N 8625197.
4. On steps 2 and 3 be sure there is adequate clutch pack clearance.
B. SEMI BONZI - Hard Shifts
1. Open 3rd clutch feed to .180" dia. in spacer plate.
2. Replace 2nd clutch wave plate with flat plate P/N 8623150.
3. Replace 3rd clutch wave plate with flat plate P/N 8625197.
4. Replace forward clutch wave plate with flat plate P/N 8625197.
5. On steps 2 through 4 be sure there is adequate clutch pack
clearance.
6. Remove the following 4 ball checks:
a. RND
b. 3rd clutch
c. 2 - 3 Dr (2 balls)
NOTE: DO NOT remove modulator / intermediate and reverse / low
ball checks.
7. Remove front accumulator spring and install piston upside down
in valve body.
8. Remove center seal from forward and direct clutch drums.
9. Plug reverse clutch feed in center support with 1/4" dia.
cup plug.
10. Rework 1 - 2 accumulator system as below:
a. Remove trim spring at bottom of the valve body bore.
b. Install 1/4" dia. copper tubing .95" long for 1 valve
or .82" long if there are 2 valves. This should block the
valve(s) out against the plug.
11. Install modified governor to get a higher W.O.T. rpm.
C. FULL BONZI - Maximum capacity, hard shifts, shifts only at W.O.T.
1. Items 1 through 10 on SEMI Bonzi plus:
2. Block vacuum modulator valve in by installing a 5/16" dia. ball
in the neck of the modulator can.
3. Plug reverse boost with 1/4" dia. cup plug in pump cover.
4. Vent reverse boost with 1/16" deep flat on large O.D. land of
boost valve.
5. Install 30.4 lb. pressure regulator spring.
(1.372 checking height)
6. Remove detent solenoid. NOTE: no vacuum or electrical
connection is needed.
7. Install modified governor to get a higher W.O.T. rpm.
D. MANUAL SHIFT - Low=1st, Intermediate=2nd. Left in drive it's 2nd
gear start and shifts 3rs at 20mph.
(For use with packages B or C)
1. Block detent valves apart with 5/16" dia. copper tubing .41"
long.
2. Remove 1 - 2 modulator - regulator valves and spring.
3. Plug 1 - 2 valve body bore vent with 3/16" dia. cup plug.
4. Electrical connection not needed for manual shift package.
Note: Packages B, C, and D should be reworked only by an
accomplishes transmission technician.
Low range can be engaged at any speed with packages C and D.
Additional welds at outer corners of converter weld nuts are
recommended for speeds over 6000 rpm.
There are axle shaft differences in 1968, 1969 and 1970 differentials.
1968 shafts have 31 tooth spline
1969 shafts have 28 tooth spline and shafts are smaller but
metallurgy is better.
1970 shafts have 28 tooth spline but a change was made from a ball
to a higher capacity roller bearing.
FRONT SUSPENSION
The following suspension modifications have proven successful for
dragging.
A. Springs
442 No. 400870 (Pontiac) Both sides. An Olds
No. 400360 spacer under the left front spring
Cutlass No. 400870 left front (Pontiac)
No. 400868 right front (Pontiac)
These springs are selected for their low rate and controlled load.
They allow the car to lift more on acceleration.
B. Shocks Cure ride 90/10. Available from speed shops
and auto parts houses.
C. Front Stabilizer Ream out hole to 1.0". This decreases
shaft bushings effectiveness of front stabilizer bar.
This hole can be reamed with a 1" stone
and electric drill.
D. Upper control arm Cut off top of bumper so that base is
bumper 3/8" thick.
E. Tires 2-ply polyester cord with narrow tread.
8.15 X 15 non-low profile
REAR SUSPENSION
A. Springs No. 9793915 Oldsmobile
B. Shocks No. 3192803 (Standard on 1969 442)
C. Control arm bushings Replace all (8) with No. 388266 (Olds)
D. Helper Springs Use Air Lift H-D type
Start with 4psi on both sides. Add air in
2 psi increments on the side opposite the
sideways motion of rear end until car goes
in a straight line. For off the road use, a
likely starting point is 5psi left and
20 psi right.
Lakewood industries is marketing traction bars that have proven
successful on some top running cars.
PARTS IDENTIFICATION - 1969
The following is a list of high-performance parts for 1969 Oldsmobile Cutlass
and 4-4-2 models. Part numbers are shown as listed in Parts & Accessories
catalog (PA 310). They are sometimes different from engineering numbers due
to packing procedures, which may include mounting parts, gaskets, bolts, etc.
ENGINES
PART PART NUMBER DESCRIPTION
W-30 4-4-2, 400 cu.in.
*Engine (Synchromesh) 230824
Cylinder head 230612
Intake valve 403350 2-1/16" X 30degrees
Exhaust valve 401762 1-5/8" X 45degrees
Valve spring assy. 404729 Silicone steel - heat set
Carburetor 7016939 Calibrated for W30 camshaft
Camshaft 402569 328degree duration on intake and
exhaust. (.475 in. lift)
Piston 400618
Distributor 1111933
W-31, 350 cu.in.
*Engine (Synchromesh) 231011
Cylinder head 230619
Intake valve 389451 2" X 45degrees
Exhaust valve 401762 1-5/8" X 45degrees
Valve spring assy. 398247 Silicone steel heat set
Piston 230645
Carburetor 7016955
Camshaft 402194 308degree duration - .474 in. lift
Distributor 1111930
RAM AIR PARTS
Air cleaner 6485003 Dual snorkel
Duct assembly-carb air rt. 403180 Fits beneath bumper - right
Duct assembly-carb air lt. 403181 Fits beneath bumper - left
Hose-duct to air cleaner 400674
Clamp-hose to duct 451245
Clamp-hose to air cleaner 400964
DIFFERENTIALS
The following differential parts are for 1969 Cutlass and 4-4-2 models.
Parts are made from high strength materials for maximum horsepower and torque
considerations. Parts are interchangeable with differentials with 3.42, 3.91, 4.33
and 4.66 ratios.
Standard differentials with 2.56, 2.78, 3.08 and 3.23 ratios are different from above
parts and will not interchange.
Differential housing 230727
Axle shaft assembly 403601
Gear set ring and pinion 230812 (4.33-1)
Gear set ring and pinion 230038 (3.42-1)
Gear set ring and pinion 230039 (3.91-1)
Gear set ring and pinion 230813 (4.66-1) Dealer installed only
Gear set ring and pinion 230814 (5.00-1) Fits 4.42, 3.91, or 4.33 case
Case assembly differential 230811
PARTS IDENTIFICATION - 1970
4-4-2 ENGINE 370 HP 455 cu.in. 365 HP 455 cu.in.
AMT SMT AMT SMT
Cyl. head casting no. 404438 404438 403686 403686
Cyl. head assy. includes 406741 405588 405586 405586
valves and springs
Cyl. head (machined) 230897 230897 230896 230896
Intake valve 403350 403350 403350 403350
Exhaust valve 401762 401762 401762 401762
Valve Spring 404729 404729 397583 397583
Carburetor
Catalog number 7041340 7041326 7041327 7036931
Rochester number 7040251 7040251 7040251 7040253
or 7040258 or 7040256 or 7040257
Camshaft 402569 402569 400165 406768
Piston "A" size 400561 400561 400561 400561
Distributor 1111979 1111977 1111982 1111982
CUTLASS 350 CU.IN. ENGINE 325 HP W-31 310 HP
AMT & SMT SMT
Cyl. head casting 403859 403859
Cyl. head assy. includes 405585 405584
valves and springs
Cyl. head (machined) 203895 230894
Intake valve 389451 399809
Exhaust valve 401762 401768
Valve spring 404729 397583
Carburetor
Catalog number 7036930 7047050
Rochester Number 7040255 7040250 or 7040253
Camshaft 402194 393859
Piston "A" size 230645 400601
Distributor 1111975 1111975
DIFFERENTIALS - 1970
ANTI-SPIN FOR CUTLASS AND 442 PART NO. DESCRIPTION
Axle sub assy. 3.42 405077 Available only during current
model year.
Axle sub assy. 3.91 405078 Production
Axle shaft assy. 403304
Gear set ring and pinion 230038 3.42-1
Gear set ring and pinion 230039 3.91-1
Gear set ring and pinion 230812 4.33-1 Dealer installed only
Gear set ring and pinion 230813 4.66-1 Dealer installed only
Gear set ring and pinion 230814 5.00-1 Dealer installed only
Case assy. differential 230811 Fits above ratios only
Differential housing 231000
OLDS W-31 SPECIFICATIONS REGISTERED NHRA LIMITS -1969
Engine type 90degree Air-inducted Rocket V-8
Displacement, cu.in. 350.30662 max. 349.82443 min.
Bore and Stroke 4.057" X 3.385"
Compression ratio 10.5 Nominal
11.55:1 Max. clean
11.85:1 Max. with normal carbon buildup
Max. bhp 325 at 5600 rpm
Max. torque ft.lbs. 360 at 3600 rpm
Cyl. head volume 60.58 cc min.
Head gasket thickness, compressed 0.023" - 0.27"
Head gasket volume 5.32305 cc min.
Deck clearance, min. .002" below deck
Min. combustion chamber volume 67.92444 cc min.
Piston type Flat
Cyl. head, part number 230619
casting number 397742
Carburetion, type 4-bbl Rochester, specially calibrated
Model w/SM trans 4MV
Model w/Auto trans 4MV
Part number w/SM trans 7029255
Part number w/Auto trans 7029255
Intake manifold casting no. 398663
Material cast iron
Camshaft type hydraulic
Part number 402195
Assembly number 402194
Casting number 389410
Rocker arm ratio 1.6:1
Camshaft timing
Opens, intake & exhaust 40degrees BTC, 86degrees BBC
Closes, intake & exhaust 88degrees ABC, 42degrees ATC
Overlap 82degrees
Duration, intake & exhaust 308degrees, 308degrees
Valves
Head diameter, intake & exhaust 2.005" max., 1.630degrees max.
Angle of seat and face, intake 45degrees, 46degrees
exhaust 45degrees, 46degrees
Lift, max., intake & exhaust .474", .474"
Springs
Outer valve closed, intake 125 at 1.670" max.
exhaust 125 at 1.670" max.
Outer valve open, intake 308 at 1.195" max.
exhaust 308 at 1.195" max.
Inner valve closed, intake Damper
exhaust Damper
Inner valve open, intake Damper
exhaust Damper
Nominal valve spring loads, closed 120#
open 300#
Wheels H-D 14 inch with 6 inch rims
Axle ratios, H-D Anti-spin available 5.00, 4.66, 4.33, 3.91, 3.42, 3.23
3.08, 2.78:1
5.00 and 4.66:1 are dealer
installed only.
Wheelbase 112"
Shipping wt. SMT, F-85 Sports Coupe 3265 lbs.
Cutlass S Sports Coupe 3285 lbs.
Cutlass S Holiday Coupe 3310 lbs.
Cutlass S Convertible 3379 lbs.
(with AMT add 37 lbs.)
To run legal NHRA wt. add 65# for 5 gals. gas & coolant
Engine I.D. No. 9,XXX,XXX stamped on front of oil
filler tube
Approximate engine weight 590 lbs. wet
SPECIFICATIONS FOR 1970 W-31 ARE SAME AS 1969 EXCEPT A FOLLOWS:
Cyl. head part no. 230895
casting no. 403859
Carburetor 7040250 or 7040255
Intake manifold casting no. 406114
material Aluminum
Wheels 15" with 7" rims are available
WEIGHTS
Weights listed below are curb weights as listed in AMA spec. minus 91#
(15 gals. of gas). This will be the weight used by NHRA for classifications.
NAME MODEL WEIGHT
Cutlass Hardtop Sedan 33639 3536
Cutlass Station Wagon 33635 3865
Cutlass 4 Door Sedan 33669 3481
Cutlass Club Coupe 33677 3429
Cutlass Hardtop Coupe 33687 3465
Cutlass Supreme Hardtop Sedan 34239 3571
Cutlass Supreme Hardtop Coupe 34257 3484
Convertible 34267 3523
4-4-2 W-30 SPECIFICATIONS REGISTERED NHRA LIMITS - 1969
Engine type 90degree Air-inducted Rocket V-8
Displacement, cu.in. 400.10671 max.
399.76725 min.
Bore and Stroke 3.870" X 4.250"
Compression ratio 10.5 Nominal
11.28:1 max. clean
11.58:1 max w/normal carbon b.u.
Max. bhp 360 at 5400 rpm
Max torque 440 at 3600 rpm
Cyl. head volume 6.975 cc min.
Head gasket thickness, compressed 0.023" - .027"
Head gasket volume 5.32305 cc min.
Deck clearance, min. 0.002" below block
Min. combustion chamber vol. 79.63804 cc min.
Piston type Dished
Displacement of dish 1.70 cc min.
Cyl. head, part number 230612
casting number 400370
Carburetion, type 4 bbl Rochester, specially calibrated
Model w/SM trans 4MV
Model w/Auto trans 4MV
Part number w/SM trans 7029254
Part number w/Auto trans 7029254
Intake manifold casting no. 398662
Material cast iron
Camshaft type hydraulic
Part number 402570
Assembly number 402569
Casting number 389410
Rocker arm ratio 1.6:1
Camshaft timing
Opens, intake & exhaust 56degrees BTC, 96degrees BBC
Closes, intake & exhaust 92degrees ABC, 52degrees ATC
Overlap 108degrees
Duration, intake & exhaust 328degrees, 328degrees
Valves
Head diameter, intake & exhaust 2.077" max., 1.630" max.
Angle of seat & face intake 30degrees, 30degrees
exhaust 45degrees, 46degrees
Lift, max., intake & exhaust 0.457", 0.457"
Springs
Outer valve closed, intake 125 at 1.670 max.
exhaust 125 at 1.670 max.
Outer valve open, intake 308 at 1.195 max.
exhaust 308 at 1.195 max.
Inner valve closed, intake Damper
exhaust Damper
Inner valve open intake Damper
exhaust Damper
Nominal valve spring loads, closed 120 lbs.
open 300 lbs.
Wheels H-D 14 inch with 6 inch rims
Axle ratios, H-D Anti-Spin
Available 5.00, 4.66, 4.33, 3.91, 3.42,
3.23, 3.08, 2.78:1 5.00 & 4.66
are dealer installed only
Wheelbase 112 inches
Shipping weight SMT, Sports Coupe 3502 lbs.
Holiday Coupe 3512 lbs.
Convertible 3580 lbs.
(w/AMT add 37 lbs.)
To run legal NHRA wt. add 67# for 5 gals. of gas & coolant
Engine I.D. number 0XXXXXX, stamped on front of oil
filler tube
Approximate engine weight 644 lbs. wet
4-4-2 W-30 SPECIFICATIONS REGISTERED NHRA LIMITS - 1970 455 CU.IN.
Bore and Stroke 4.125 X 4.250
Compression ratio 9.64:1 Nominal
11.148:1 clean
Max. bhp 370 at 5400 rpm
Max. torque ft. lbs. 500 at 3600 rpm
Head gasket thickness, compressed 0.023" - .027"
Head gasket volume 5.32305 cc min.
Deck clearance, min. 0.002" below block
Min. combustion chamber vol. 91.71971 cc min.
Piston type dished
Displacement of dish 1430 cc min.
Cyl. head, part number 230897
casting number 400370
Carburetor, type 4bbl Rochester specially calibrated
Model w/SM trans 4MV
Model w/Auto trans 4MV
Part no. w/SM trans 7040251 or 7040256
Part no. w/Auto trans 7040251 or 7040258
Intake manifold casting no. 406115
Material Aluminum
Camshaft type Hydraulic
Part no. 402570
Assembly no. 402569
Casting no. 389410
Rocker arm ratio 1.6:1
Camshaft timing
Opens, intake & exhaust 56degrees BTC, 96degrees BBC
Closes, intake & exhaust 92degrees ABC, 52degrees ATC
Overlap 108degrees
Duration intake & exhaust 328degrees, 328degrees
Valves
Head diameter, intake & exhaust 2.077" max., 1.630" max.
Angle of seat and face, intake 30degrees, 30degrees
exhaust 45degrees, 46degrees
Lift, max., intake & exhaust 0.475", 0.475"
Springs
Outer valve closed, intake 125 at 1.670 max.
exhaust 125 at 1.670 max.
Outer valve open, intake 308 at 1.195 max.
exhaust 308 at 1.195 max.
Inner valve closed, intake Damper
exhaust Damper
Inner valve open, intake Damper
exhaust Damper
Nominal valve spring loads, closed 120 lbs.
open 300 lbs.
Wheels H-D 14 inch with 6 inch rims
H-D 15 inch with 7 inch rims
Axle ratios, H-D Anti-Spin
Available 5.00, 4.66, 4.33, 3.91, 3.42,
3.23, 3.08, 2.78:1 5.00 and
4.66 are dealer installed only
Wheelbase 112 inches
The following weights are curb weights as listed in AMA minus 91#
(15 gals. of gas). This is the weight used by NHRA for classification .
MODEL MODEL NO. WEIGHT
Convertible 34467 3753
Club Coupe 34477 3726
Hardtop Coupe 34487 3726