29 or 30 inch by 9 inch wide (or so) is probably the biggest tire you could fit w/o some modification.
235/75r15 is 28.8x9.25 and is considered a +1 size for a stock Cherokee (and what was on my Jeep when I bought it).
Have you looked at what size tires the kit will clear?
RC's kit, for example, says it WILL clear 31x10.50.
You will probably want to install bigger bump stops (or add hockey pucks; Google it!) regardless.
Are you sure you want to spend the money on a lift to get such a small increase in tire size?
