Aight man it all depends on the backspacing of the rim and the width of the tire. 33x12.50's on 18x9"s are going to hit. The only way your going to get away with running that tall of a tire is to go with a rim that has backspacing like the stock rim has and then your 12.50" wide tire will probladly hit the upper arm. Go for alil skinnier tire and I think you will be ok.