i have seen this posted in a thread but i can't find it. 70 cutlass with TH400 and O type rear. what length is the drive shaft? i went from 4sp to TH400. i have a yoke and about 20 drive shafts of several lengths. i know one is out of a 70 442 with this setup but don't know what one it is.

 

The 400 shaft should be 54 1/2" center of ujoint to center of ujoint.