Unless you plan to drive it at the time, simply starting for a few minutes WILL do more harm than good. You'll be creating acidic moisture that in the exhaust and oil, but the engine and exhaust system won't be run long enough to vaporize it all. If you are going to store the car, remove the plugs, squirt some oil in each cylinder, rotate the motor to distribute, and reinstall the plugs. Drain the carb (or run it dry). If you can't drain the gas tank, at least use some fuel stabilizer. Remove the battery and trickle charge it. Keep the tires off the ground, but support the car under the suspension so the springs are at ride height.