been through two RPF1 setups where my current sizing is 18x9.5 +38 with a 265/35 tire. I needed a 10mm spacer to barely clear my OEM calipers with the 13" rotors. You will have a perfect amount of clearance if you get a 10mm spacer. Plus, you can still run a 265/35 tire up front on that 9" wide wheel for a nice meaty setup.