These brakes do clear almost all common 15 inch wheels. I have used them with Rota Slipstreams, Buddy Club p1s, and Spun SPK-Gs without modifying the brakes at all. Wilwood's website says minimum 15 inch wheel and has a diagram to show what pattern wheel and offset will clear the caliper and rotor.

I have had no issues at all fitting these under 15s. On the Rota slipstreams they sit very close but no problems.