6. We procured a set of Baer calipers and rotors through their Builder Series program. Using our own hubs in conjunction with the Builder Series parts, allowed us to put the wheels in the exact location necessary to run the 275/40-17 tires up front. The two-piece Baer rotor is 13 inches in diameter and is 11⁄4 inches thick. The aluminum caliper uses Mustang dimensions in order to work with the Bullit wheels. These rotors weigh 18 pounds each, which is 5 pounds lighter than the Viper rotors that were on the car.