you'll find more info from some 4x4 forums but to answer you question i'll try to help first off do you have a 2wd or 4wd? what size tires do you have now? do not exceed a 3" body lift for saftey and liability issues. also going to a 4" back space rim will pust the tire out and rub sooner. make sure you ubderstand the back spacing properly. 35" tall tire would be the size i'd recomend with the suspenion and the 3" body. if you have a 6" and the 3" body you can go 37"