i had 31's and stock for the longest. only on full flex in the rear only, and full turns did i have a problem. and it wasnt bad, not like ripping apart my tires or anything. just some slight rubbing. and you can adjust the bumpstops for clearance. turning bumpstops are on the knuckles, and the rears you can add plates or rubber to compensate.
but, for the price of a 3" lift i'd just go that route. it's only 500 bucks, and you can get some decent ford rims from the junk yard with 31's on it for 200 bucks and go from there. there are tons of explorer/rangers out there running a 31. or, get some spacer/adapters and go for the f150/bronco wheels/tires.
any way. i dont know clearance numbers for crawling, but mud was never a problem for my xj, even stock. but, i'd aussie the front at least, and if possible and you know what you're doing, ford 88 the rear with a lsd.
1994 jeep cherokee, xj, 3" rough country springs / bilstein 5100's, 31" tires with trimmed fenders, aussie locked front diff, herculined ext, hella FF75 driving lights on factory fog location
[COLOR="Lime"]soon to be[/COLOR] 4.11 gear and and a ford 8.8 LSD rear and herc'd interior