Lots of threads out there that give great examples with pictures, but I think the general rule is about 4.5-4.75" of backspacing and a width of 8-9 inches. You can run a wider rim, but you may have issues keeping the bead seal if you run low pressure off road.
Oops... a minute too late. I just saw the previous post as I finished this one.
Last edited by rgeorge33; 06-21-2015 at 05:49 PM.
Reason: Redundant information.