trying to figure what size tires i need bc im tryin to trade a guy my 17" cobra r's for his 18" 03/04 cobras. both sets are 9"/10.5" wide. right now im runnin 255/45/17 on front and 315/35/17 on rear and i have an eibach pro kit lowering kit. what size tires are you all running with 18's? any rubbing issues? thanks fellas!