I I would really like a turbo 400 in my truck

[kwmech]

203 transfer cases do not have to be bored out, they already have the 210 bearing in them, you will need the 400/203 adapter and a 32 spline input gear for the gear box and have it swapped in--which is a chore in itself---not hard but time consuming as you have to separate the 4x4 chain box from the low range gear box. If you decide to go through with this I should have the parts sitting around here somewhere.


Looks like OP edited his parts. Same still holds for parts. Adapter and input gear, but also the 400 needs the proper output shaft for the thickness of the adapter. The 208 is a lot easier to rebuild. I do not have a gear for the 208, but they can be had for about 100-120 dollars, plus a good time to rebuild it with new bearing, fork pads and a chain. I have an adapter and possibly the output shaft needed for the 400