5.2L to 5.9L swap
I have this swap completed in a 96 ZJ, if you have any questions feel free to ask. I used a 98 dodge ram 5.9L engine and transmission.
Issues we ran into: Because I used a dodge ram transmission, we had to accommodate a starter on the driver side, did so buy cutting the end of my starter wiring, soldering in a battery cable and some connections to fit the starter. Looped the wiring loom with the bottom of the oil pan bolts so it looks clean/tucked up. I had to swap the driver side engine mount with a 98 ZJ 5.9L (I replaced both engine mounts mine were toast). You will need headers, you can use the stock exhaust manifolds, the exit/collector drops right at the new starter, I used Hedman Tight Tube headers +spent about $800 on a custom y-pipe, high flow magna-flow catalytic converter, and a magna-flow magnapack muffler. Had to rig up a bracket for the transmission shift linkage/kick down cable.
R&R: We pulled the front clip (radiator, condenser, grille, etc.), and the hood for enough clearance, removed the accessories/bracket (p/s, a/c, alt) and removed both engine and trans. We bolted the new engine and trans together before we stabbed it in, with enough angle dropped her down in. (re-install the accessories after dropping the engine in). The only other wiring problem we had was with the coolant temp sensor, cant remember if I needed a different connector or just had to lengthen the harness but that was no big deal. Everything else clipped right in.