Thick Case Short Shaft Turbo 400 Transmission , pretty sure this has A Manual Valve Body and Definitely has the High Capacity High Gear Hub , should be gone through, has been sitting over 25 years. $800
It’s a Pontiac but I Believe Buick and Oldsmobile have the Same Bell Housing
Thick Case Transmissions come out of Big Body Cars , they have a Long Shaft Originally but the Case Is The same as A Short Shaft so You take The Guts Out , scrap them and Install the Short Shaft Guts , Now You Have a Much Stronger Bell Housing for Racing.