I read a post about this stuff but it didnt make sense to me so in a nut shell...i did a 3" lift on my xj and bought 31x10.50x15 MT's and i am going to mount them on my stock xj wheel for now...i know that will probably rub and as soon as i get the money i will get a 15x8 rock crawler....my question is what is the closest offset to the stock 5.25 that i can get w/out worrying about rubbing. My main goal is to not have to get bigger fender flares b/c my tires stick out too far. (NO money right now) Thanks for any info.

On a TJ those will fit on the stock wheels fine, with maybe one washer added to the steering stops. Not sure about XJs.

AR 767s are available with a 4.5bs and Tech 1s are available with 4.75bs. Either one will work for you.

I wish I could remember this stuff. I found a good site with a Jeep that lokks pretty close to yours: http://www.angelfire.com/pa5/mcfranson/ He's using 3.75 backspacing and the tires look like they stick out some. Maybe knock it down and get some 4 inch or 4.5 or 4.75 back spacing. If they rub, you can adjust the steering stops. :D

dont forget the rear springs
with a stock offset 7.5 rim they are mighty close to my 35x 10.50s
not like a yj they sit out farther or the dif is smaller drum to drum

Dont know if this is much help, but here it goes, I put 15x8 on my tj with a 4.5" back spacing with 33x12.50 BFG MT's, I only have a 2"bb and they stick out a little, I only hit the lower control arm on a hard lock turn but barely noticable