oldsmobilejim

Hello I have a couple questions. Is a driveshaft for a 350 turbo or a 400 turbo the same other then the length? Are the yokes interchangeable?
Thanks Oldsmobile jim

70W-32

Nope, they have different spline counts, with the T400 being larger

joe_padavano

No to both questions, actually. The yoke is larger on the TH400 and the center-to-center length is different since the TH400 is longer. Also be aware that driveshaft length is also different depending on the rear axle. The pinion flange-to-axle centerline is different on the different axles. And of course wheelbase varies with body style for some years and models.

Phoenix8990

When the PO installed the 455 w/TH400 trans in my 69 they had the driveshaft shortened. As I tried to clear up some vibrations in the car I found that they had not had it rebalanced. It made a difference.

Steve

Allan R

If you're converting from TH350 to TH400 you'll also need to move the trans cross member, change your intermediate e brake cables and hooks as well as install the proper kickdown linkages for the TH400.

joe_padavano

Apparently the OP is actually changing from a 700R4 to a TH400 (based on a PM to me), so it isn't clear where the crossmember or cables are right now.

oldsmobilejim

700-R4 replaced with turbo 400. In regards to cross-member and emergency brake cables. The cross-member fore and aft align to the same holes for the 700-R4 and the 1987 turbo 400 so same brake cable will work... Go figure I don't have that kind of luck! Yahoo.
I stand corrected the 700-R4 is a 1987 the 400 turbo is period correct BOP, and the cross-member does not align to the same holes nor does the brake cable work...