4.0L and AW4 Interchangability

I am currently looking to swap out my 4.0L and AW4 tranny in my '95 XJ for used units. (Motor and tranny were shot when I purchased). From what I understand the AW4 tranny can be from any cherokee '91 and up (due to the 23 spline shaft that was introduced in 91). As far as the 4.0L can I use any 4.0L from '91 and up? I know that they did some revisions in 1996 to the head design. I also thought they swapped a couple sensor locations (coolant sensor for temp gauge?).

Would I be able to swap any 4.0L '91+ into my '95 XJ?

Would I be able to swap any AW4 '91+ into my '95 XJ?

To do a direct swap i would just get a motor and tranny from a 91-96.

I dont know what changed in the transmission between any of the years, but the motor (to do a plain jane direct swap) youll definetly want to get from a 91-96 (your year's era).

Thanks, I knew there were some changes in '96. Do you have any idea what those changes were? If I find a low mileage 4.0L that is newer then '96 for a good price would there be many points of concern?

The sensors changed slightly (internally) in 1996 for OBD-II, and the main bearing brace was added. Also, the cylinder head was revised in 1996 (#0630) with slightly smaller exhaust ports than the #7120 (1991-1995) to allow the catalyst to reach operating temperature more quickly. However, any AMC242 cylinder head will go on any AMC242 block, so you could swap out pretty much any short block and retain your head.

For a more direct swap (using all donor parts,) you could just get a 1991-up engine, but you'll note performance suffering slighting if you get the 0630 or 0331 head. As Muad'Dib mentioned, you're probably best off getting a 1991-1995 engine (although, even the RENIX-era - 1987-1990 - would work, just swap the head.)

Alright, sounds good. I will just pick a used motor and tranny from a local yard then (and make sure it is 91-95). Thanks for answering my questions.