GM 10 & 12 Bolt Rear Disc Brake ConversionA-Body/F-Body/X-BodyNon-Staggered Shocks Note: Rotor Center = 2 3/4" - Rotor Hat Section Inside Diameter = 6 3/16"You will need to modify your axles if they will not fit inside the rotor hat and you will need to modify the rotor if the center hole is too small for your axles.