I guess it really depends on what you want, and how your giong to use your rig.

I'm one who likes to keep the center of gravity (cog) low and go wider. I'm running 35's on my XJ with only 5" of lift. The wife is running 33's on her XJ with 3.5" of lift. Now given I've trimmed on mine (5" & 35's), but on the wife's rig we have not trimmed much at all.

I'll also say I'm not fond of 33 x 10.5" tires. I don't think that they sit wide enough and I think that the extra 4" (2 inch on each side) that going to a 33 x 12.5" tire offers helps a lot. It made a world of difference going from 10.5" to 12.5" tires on the wife's XJ; so much so I actually enjoy driving her rig again on the road.

I think the reason the skinny tires are popular is that people think that they can run a larger tire, but still "stuff" it into the fender well better. What they dont' factor in is the offset of the rims that the tires are mounted on. I also don't understand why everyone is always so concerned about uptravel and don't care squat about downtravel when it comes to suspension. You'll actually ware out your suspension componets faster by over compressing coils and leafs with huge amounts of uptravel. Bumpstopping is key; not only in helping to preserve the life of suspension componets, but also in keeping tires out of fenders/flares etc. Not many wory about bumpstoping, and I think it's one of the most important overlooked factors in doing a lift.

With all that said, you do what you want; as it's your Jeep and your money. I'm not going to sit here and try to tell you what to do, but I will offer advice as I've been threw many lifts on the XJ's at different heights and different tire sizes.

Lets talk about my wife's rig. She's running the RE 3.5" lift on a set of 33" Maxxis Bighorns. The tires are 12.5" wide and were running them on a set of 15x8" rims. The rims have an offset of 4". I will also say at this point that this XJ is her daily driver.

Here is a pic just for referance;



We have NOT trimmed a thing in the rear. It will flex just fine and stuff the tire just fine in the rear (bumstopped correctly). In the front we have trimmed just a smidge, basicly to get clearance at full lock. She was adimit about keeping her factory flares, so I wasn't allowed to cut much. This pic here shows what we trimmed. It was basicly from the body line down on the flare, and than about a 1" x 4" peice of metal out of the bottom of the fender.



What we've done than is bumpstopped correctly everywhere to keep things out of the fenders. When you bumpstop, as your axle cycles you actually get better flex by hitting your bumpstop, as it will force the other side of the axle down, and you'll have much better downtravel. Everyone thinks it hinders flex. I'm here to tell you it won't. I can score the same RTI score with her XJ (3.5" on 33's) as I was able to with my XJ when it was on 4.5" and 31's.

What we've saved going with the 3.5" lift in price we were able to upgrade to other things like a heavy duty trackbar/bracket, heavy duty tie rod, OME shocks, trackbar brace, etc.

Just my penny and a half worth, but I wouldn't go higher than 4.5" to run 33's and really consider going with a 12.5" wide tire.....

might look at a fab tech 4" check out motion offroad they specialize in XJ, and they are reasonably priced cold air intake , spacer , and exhaust/header helps