i like no bigger than 18's on my trucks with the right tire and wheel setup but if you can run bigger and keep it from lookin stupid than do it, im runnin 18 inch rims on 33 inch tires on my 2500, cummins pride tyler shit looks good man what kinda hp and tq numbers you seeing on that thing? Ive got 507 hp with 790 ft-lbs on my 2001 keep burning the damn vp pump though