i would stay away from the 00 and 01 models unless you find a really creampuff example (but then what kind of ZAV would that make?) as the cylinder head castings changed and they all too often crack eating coolant and requiring a new cylinder head. i hear you can swap a pre 00 with some modifications or a grand cherokee or wrangler 02+, but i'd rather simply have a good head to start with. 99 and before have distributor ignition too, for better or worse, though certainly easier. 97+ also have the somewhat stronger 29 spline axle, while most 96 and all 95- have either the d35 or 27 spline 8.25.
i just sent my rusty old 88 cherokee shell to the scrapper :( but while she lived i built a 4.7L stroker out of the 88 renix block with a 92 High Output head, swapped the noisy d35 for a free 27 spline 8.25, eventually lifted it 3" with 30" BFG ATs and found myself needing either a transfer case drop and axle shims but went for AvanceAdapters slip yoke eliminator kit (the ONLY mod ever on my jeep to only fix problems without creating new ones
) i also put grand cherokee disk brakes and backing plates on when i put a No-slip locker in it (without problems even with lots more power, bigger tires, and a 27 spline).
i found a really streetable and reasonably flexy 3" lift using quadratec's HD replacement leaf springs, a 2" budget boost (front spacer, longer shackle, and 1/2" plate), and front v8 grand cherokee ZJ springs.
before she rotted out on me it was an animal in rough conditions and even without crazy lift it went really far with just the locker. plus with the disks on the c-clip axle and locker you can still get away from the zombies if they find a way to break an axle without losing the whole assembly out the end of the axle.
