Quote Originally Posted by offgrid View Post
T150 transmission, Dana 20 transfer case.

My brother in law has a AX15 transmission and Dana 300 transfer case I can have for free.
The T150/D20 combo will hold up to a 350 fine, but the gearing is pretty poor on that 3 speed if you want to do any off-roading. The AX-15 is a decent transmission, but I've only run one behind a 4.0 I-6 on my old XJ. I'm not sure of the durability behind a 350. The D300 is a great transfer case and will hold up well.

The weakest link in your drivetrain will be the AMC20 rear with the 2pc axle, assuming it's currently stock. You're going to want to either upgrade it with either 1 pc axles or a stronger rear end like a Dana 44.