Girodisc Ford S197 Mustang GT500, Boss 302, GT (Brembo) Front RotorsThe Girodisc system is a direct replacement for the OE disc. No modifications are necessary. The disc will bolt directly to the car and work with OE calipers perfectly. By upgrading your brakes with lightweight high performance replacements as opposed to a big brake kit, your factory bias is maintained as well as your ABS efficiency. The Girodisc front rotors are approx 20. 2lbs vs. 25lbs for the stock units. This reduction in rotational and unsprung