I don't know the answer to your final question. However, if you really want to keep the stock ride and handling, a two inch budget boost with blocks in lieu of the add-a-leaf rear worked well for the GF's Cherokee. The 30" tires don't need re-gearing for the auto-tranny, and the spare fits on the rear sidewall where the donut was. A 31" prolly wouldn't fit - it's that close. It has done very well on some difficult trails. Also added were recovery hooks in front and a rear receiver for a winch I have mounted on a ball hitch (welded) with 20' twist-lock welding leads to go to the battery when needed (thanks for that idea BJ). It looks like that was the way it should have been built to start with. <img src="/forums/images/graemlins/smile.gif" alt="" />