TH350 to TH400 swap

[ECU PIRATE]

I know this has probably been covered before but, I just needed a little clarification for piece of mind and pocket..........I am looking to swap out the Olds 260/TH350 combo in my truck for a Chevy 350/TH400 set up. 87dually burb and I are discussing a trade on a Chevy TH350 I am planning on picking up for a song.

The question is, will the auto crossmember out of a 84' 2wd Burb, fit in my 82'? The PO hacked mine to pieces to fit in the drivetrain from a 76' Olds Omega. I know I will probably need to get a new drive shaft or pull one from the junkyard and have it cut down. All of this just to plan for a future BBC swap down the line

Thanks,

The Pirate...........

[BLE 'BURBAN]

TH400's came in 3 different lengths.
1. 4wd configuration
2. 2wd Short shaft configuration
3. 2wd Long shaft configuration.

The 2wd short shaft is the same length as a TH350. therefore you won't have to move your crossmember or shorten your driveshaft. You will however have to change out the tranny mount and the yoke at the trans because they are differnet as well between the 2 tranny's.
If you're getting a long shaft then you will have to move the crossmember back on the frame (should already be holes in the frame for this)
You'll also need a kickdown switch for the TH400 which you can find in a wrecking yard. It's mounted on the accelerator bracket at the top.