I understand that the Chevy deisel of the late 70's and early 80's was actually an Oldsmobile setup. Would anyone be able to tell me if the TH400 is specific to Olds, or is one able use a standard Chev TH400 as a replacement. What I have is a 1981 Chevy half ton 2 wheel drive that came from the factroy with the Diesel and TH400. The transmission has failed and must be replaced. I am having a difficult time finding industry knowledge that would answer the question. The bell housings, are they different for the Olds bloack? The engine was swapped out some years ago with the Olds 350. Whay wasn't a Chev motor used? Is it because of the drive train? Thank you in advance.
I believe the turbo 400 transmission and the turbo 350 transmission came with 2 bolt patterns, one fits smallblocks/bigblocks (only), the other has a "universal bolt pattern" that will fit either chevy or oldsmobile engines. I believe the universal case has more holes, and comes to a point at the top (^) versus the kinda straight across one that the chevys use. I think that the first diesels chevy came out with were actually modified oldsmobile 350's .... If that is true, it would have been easier just to slap a regular olds 350 in its place So if you have the olds 350 in it I believe you will need the "universal case" 400 in it's place. Any one else have any info?? I hope this helps you.
The only thing with GM Transmissions is: Trannys for BOP {Buick,Olds,Pontiac} are set-up for starters on the driver side of the engine. All other trannys are set-up with the starter on the passenger side. Where the starter on your engine is , dictates what transmission you need to find. vince
Yes the olds has a different bolt pattern, I believe in old school terms it was called the buckeye trany.
Hi, i 've joined a scan of different transmission dimensions. Hope this will help. F.J. Attachments: https://talk.classicparts.com/images/attachments/40478f3a0868ccce.jpg
Cant the shop just replace all of the guts in the tranny and use the same case? Where are you located, I actually want to put an olds engine in my truck and may want to pick up that case.
