Widest tire you can get without changing backspacing is going to be a 9.50 or 10.50 depending on manufacturer. More than likely, it is going to be the 9.50. I ran with a 3" lift, uncut for years and the widest I could do was 10.50 and that was having to either cut the inside drip rail off the fender or flatten it back against the fender it'self. Even doing this, if I got into a frame twister spot on the trail, it still would touch when the tire went into a stuff position.