I have a 09 dodge 1500 with a 6'' suspension lift with a 3'' body lift i am trying to fit 38x15.5x18 but im having a problem finding the right wheel for them. i tried a 18x10 and no luck. Should i go with a half inch spacer, replace the studs and go a little higher so i wont rub the fenders? or go with a 18x12 wheel

 

18x10 vs 18x12 will not solve your problem. You have an offset problem. Figure out what offset (backspacing) your current wheel is and find one that has less backspacing. Also plan on going through suspension parts like crazy with tires that size on stock drivetrain.