33s if you're not going to regear. I'm currently in the process of stepping up from 31s to 35s, gears, and long arms

 

33 change the jeep alot and anything bigger than that your looking at changing alot of stuff on the jeep. I like my 35s but also ran my 33 till they were gone before stepping up.

 

i think 33's are biggest & best size for xj's , unless massive changes are made. after 33's brakes should be upgraded, chromo axle shafts or the breakage factor goes way up & safe on the street goes way down. 33's & lockers will take a xj almost anywhere you point it, i had a built cj once w/ a 44front & 9" rear both locked, went from 35's to 37's main thing i gained was more broken drivetrain parts, wasnt worth the 1" of clearance.

 

I love my xj on 35"s probably gonna go 37" once my waggy44 is done but it's a lot of money I just dropped close to a grand building new steering and rehabbing the front end. Not to mention 4.88 gears and 8.8 swap I did last year along with all new bushings then. It all comes down to how deep you want to dive in and is it necessary I'm getting ready to trailer mine to Florida on the first because I'm moving that's why I'm going ***** deep again.

 

My truck went anywhere I pointed it with 33s locked front and rear. I popped a tire and got sick of dragging diffs so I moved to 35s bump stopped more and cut a little more. I love them. But gears are struggling, not horrible but on the road is bad.

 

In the past 2 years I went from 31's to 33's to now 35's on my 3.5" lift. and it's staying with 35's. The clearance is great and also I like to make people wonder how I get my big tire'd XJ with a little lift flex like it does w/o rubbing.

 

^^fancy magic tricks of course

 

I went straight from 31s to 35s.
If your considering them now you will regret not getting them.
Make sure you do the proper upgrades for that size tires though.
(No d35, no low pinion d30, 4.88 gears, better brakes and steering)

 

I went from 31's to 34 super swampers and am loving them.4.88 gears will be soon to help out.plus I'm locked front and rear

 

Yes. Bump stops are amazing lol

 

35"s if your planning on going higher . I started with 4.5 inchs on 31s , got to 9.5 inchs lift and 35"s . had the 35s at 6.5 and just added more . it also depends on your back spacing and rim size . my 35x12.5x15s are on a 15x10 rim , I got lots of traction and a stiff ride , but lil ware on the treads . the tires don't balloon out and ware unevenly when you have a proper rim , the recommended rim size for 35x12x15s if I remember correctly was 8.5 or 9" , but good luck finding a rim that size not on special order.

 

Ya i wouldn't go any higher then 5.5" with 35"s I was at 7 when I bought mine and ended up lowering it because it was unstable and the drive line geometry was never right and it looked goofy. And Yes it was done right. As far is rim size I went from 10" to 8" both 3.75" offset the jeep and I couldn't be happier.