I have 15x8 with 4.5 bs and with 245 60 15 I could not put tip of pinkie finger between wheel lip and tire. I have a second housing we narrowed to 51 5/16 I will use. The new problem becomes spring clearance, the 1/2" gain on each side will help a bunch. TTI told me I could not use my 3" tail pipes if I did this.