I have a friend who has a 1985 vette th700r transmision, I want to swap my 1977 , 400r for the 700. How musch of a problem will this incounter? Can a direct swap out be done or does drive shafts have to be cut and shortened? what kind of a head ach am I getting into??

 

First of all, you will have to get the 700R upgrade wiring kit from Painless Wiring to use to operate the lock up conveter in the the 700. Early 700's use a vacuum switch and a pressure switch to lock up the converter in 4th gear for direct drive. It requires about 2 hours of work, because you will have to drop the trans pan to install the wire, hook up your brake light switch and install a vacuum switch and a fused wire to the solenoid in the transmission. Later versions of the trans, 4L60, had shift solenoids and the lockup solenoid all were controlled by computer. Modiying the driveshaft and such all depends on the length of the tailshaft housing on yours compared to the 700.