The ZJ disc mounting brackets will need to be opened up a little in the center hole and maybe in the 4 mounting bolt holes. Not a big deal to make it work and well worth it just to stop adjusting drum brakes.
If it is V8, grab the tie rod.
Grab the seats. You'll have to modify the seat brackets to get them to fit a 91 but may be worth it.
If it is v8, the front coils will net you 1-1.5" of lift. If V8 upcountry, 2-2.5"
If it has discs, get them.
Take the sway bar links for spares.
The wheels are probably nicer than what is on your rig (just guessing)
The booster is going to be dual-diaphragm, so unless there are ABS issues grab it and swap it in.
Prop valve, if you get the discs.
Thats all I can think of...
