The AFCO F33 caliper will give you the best caliper in racing. The caliper has 1 3/4" forged pistons and is designed to be used with an 3/8" wide rotor on a 5.25" bolt pattern. The caliper is 30% stiffer for better feel on and off the brakes allowing the brakes to have the least amount of drag possible. The caliper features stainless steel abutment plates, one piece high flow bleeders that use a 7/16" wrench, internal cross over passages, extreme duty bridge bolts, a forged caliper body, and forged truly round pistons.