i just got BFG All-Terrian T/A's for my 95 wrangler in 30x9.5's and they fit great and i guess u could fit 31's but if u hit a bump they would rub, even with my 30's i just recently put a 2in body lift on and that cleared them up alot, it all depends if u want your tires to rub or not, i'm planing to even put TJ flares on my wrangler to have even more room, its really up to do, but if u got a 4cylinder like i do, your gonna want to go with the 30's i think, and don't forget your speedometer is gonna be messed up too because of the bigger tires. plus if u got 6.5 inch width tires, i don't think u can fit 10.5's on it those can u?
have a good one
1988 Wrangler Laredo 4.2L w/5spd Manual
1995 Wrangler 2.5L w/ 5spd Manual-dixie horn