I assunme you mean a Dana 20 transfer case? The AMC 20 is a rear axle.

Fit depends on the particular transmission you have. I suggest that you find out the designation fo the particular tranny you're talking about, and then call Advanced Adapters and find out if it will fit direct, or if you will need an adapter.

1977 CJ-7, fiberglass body, AMC 360 w/ headers, DUI ignition, Edelbrock intake and Holley 4150 carb, TF999, Dana 300, 4.56 gears lockers, York air comp, 4" susp lift, 2" body lift, BFG 35" M-T tires, Megashifter, AGR pump & box, REP8000 winch.