Long answer. If you have the stock rear axle location, and a stock rear bumper, people say a 33" will fit, if you beat the stock spare tire locater tabs out of the way. Probably true. If you have the All-Pro rear bumper, with the recessed/hidden hitch, I think a "33 will fit but I'm not sure. I have the All Pro rear bumper with hidden hitch, and I also have All Pro rear springs. The All Pro rear springs push the rear axle back 1" from the stock location, and I can't fit a 33". 32.5" is about a large as I can go. I have a stock jeep JK tire as my spare, which is about 32.5. But I can see a rub mark where the tire hits the diff when I get some compression.
I'd really rather have pizza cutters, but I know I can't that under the bed with my springs/bumper.