I was talking to a guy that has had several a-body cutlass'. He told me that the drive shaft is the same length when equiped with the TH350 or Th400 and only the yolk is different. Is this true? I always thought the transmission length difference was made up with the length of the driveshaft. Does anyone know if this is true or a myth?

 

From what I remember most A-bodies 68 to 72 and maybe older too have the same driveshaft length with the yokes bigger on the turbo 400....I am not sure this is true if replacing a 2 speed Jetaway with a turbo 350 or 400...best thing to do would be to measure first.

 

not a 100% sure but I think a short tailed 400 is the same length as the 350, but some 400's were long tailed...and I also believe that a 350 is the same length as a powerglide...

 

I don't doubt that the two are not much different and innerchange for the most part. Be careful, the lengths are different. The 400 is 3/4" longer than the 350 when comparing short shaft housings. Hence, the 400 shaft is 3/4" shorter in the same application.

The 400 shaft should be 54 1/2" center of ujoint to center of ujoint. The 350 shaft 3/4" longer.

If you use the 350 shaft with the 400 yoke and 400 trans, you could run into binding at the bushing in the tailshaft because of excessive length and damage it. This won't allow the rear to swing its arc of motion smoothly.

And then, the spicer/dana differences. Depending on where the car was assembled and available suppliers at the time.