i have a 3 gear trans, and im trying to replace it with a 4 gear trans, the car is Automatic. is their a trans i could swap it with out doing that much work?
the only 4 speed auto I know of is an aod. It will require a new crossmember possibly flexplate. The driveshaft may need shortened
Any AOD from 88 to 93 302 / 5.0 will work but it take a little work. If this is a stock engine and the gear ratio is stock too then you are not going to enjoy the swap much - In overdrive your car will be gutless (the effective gear ratio is about 2.3:1) so acceleration will be zip! I doubt that you will get much, if any mileage increase over stock with the AOD. You will need a cross member, Lokar throttle pressure cable kit, possibly a driveline (depending on the AOD you get) and the engine plate from the donar car to match the bellhousing.
I believe he would need a different flexplate too. As far as I know an aod uses a 164 tooth and a small bell c4 uses a 157 tooth.