you should be able to run 31x10.5's with the stock suspension just fine. You just might need to get the steering stops adjusted so that you don't rub at full turn. Some jeeps need it, some don't. Mine did when I had stock suspension and 31x10.5 BFG AT's
Sold after ten+ great years 1997 Jeep TJ Sport
Currie adj arms AEV 3",1.25"JKS BL,1" MORE MML
BCC bumper/tire carrier.
Warn xd9000i, 35x12.50 MT/R's, SYE/CV driveshaft.
8.8 with 4.56's front and back with an Aussie Locker up front. Poison Spyder HD steering upgrade.