If it's already got a BB (budget boost), you will see a poly-type 2" spacer between the top of the springs and the spring seat. It's easy to see on the front. My '98 runs 31's with a 2" spacer and there is tons of room, could prolly run 33's without much problem.
Corona <img src="/forums/images/graemlins/cheers.gif" alt="" />

'98 TJ, 4 cyl., auto
31" AT KO's on rockcrawlers,
custom bumpers, Hellas
2" Teraflex lift, no top,
no doors, no problem.