Originally Posted by no rdplz

31's will fit with a 2" BB lift and on your stock 15x7 rims. However, they will rub on the LCA's at full lock and any time you flex the front axle. A 3" lift will clear your 31's, but you'll still have the same issue with rubbing at full lock. There are two ways to fix this:
1) 1.25" wheel spacers. This is, in all honesty, a bandaid fix and even though it works, I would opt for #2 if possible. I currently have 1.25" spacers, but am saving up for a set of backspaced rims so I can lose the spacers.
2) Properly backspaced rims. You'll want to find a rim that has at least 3.75" backspacing. Lug pattern 5x4.5, and a 15x8 size. You could go with a wider rim, but then your tire sidewall doesn't protect the edge of the rim as much.

As for rubbing while flexing, you may still get some rubbing on the front bumper caps. Easiest fix is to remove them but it looks like crap IMO. Do a nice trim job on them, and you'll keep a "finished" look to your XJ and not have to worry about rubbing anymore.

If you're looking at a 3" lift, Rough Country (RC), Rusty's, and Rubicon Express (RE) are going to be the top three recommended. RC is going to be your cheapest kit. In my experience they ride a little rougher than Rusty's, but performance and quality are about the same between the two. Rusty's is going to be your "middle ground" for price. I paid the extra $$ on Rusty's 3" for the better ride and have been extremely pleased with how it's performed on and off the road. RE is going to be the most expensive of the three. Some swear by it, but from what I've seen, it's no different than the other two except in price. It's the most established of the three, so you're pretty much buying the name IMO.

Hope this helps.