I have the CPP 5 lug conversion and 15" rims. The rotors are from an early 70s chevelle and calipers from a mid 70s Camaro. The rotor is 11" and I have about an inch clearance between the caliper and the the wheel. 15" rims and a 12" rotor is going to be awfully close.
By the way, my entire kit, which included a master cylinder and booster, was only $600. Take that for what it's worth.
