Description:Product Item: The product Gm 10 12 Bolt Rear Disc Brake Conversion Kit, (does not fit all 10 & 12 bolt axles)Material: The bolt on rear disc brake conversion kit is made of metal material, is sturdy, and long service timeEasy To Install: The bolt on rear disc brake conversion kit is easy to install and do not require complex steps to complete the installationHigh Performance: Professional manufacturing bolt on rear disc brake conversion kit, sturdy and stable performance, rotors have both 5 on 4-1/2" and 5 on 4-3/4" bolt circles, fits axle with a maximum flange diameter of 6-1/4" O.D. 2.780" rotor center holeDirectly Replace: Directly replace the old or broken bolt on rear disc brake conversion kitSpecification:Material: MetalFitment:For Buick Skylark 1964-77 For Chevy Chevelle 1964-73 For Chevy Nova/Chevy II 1964-79 For Chevy El Camino 1964-77 For Camaro 1967-69 For Chevy Monte Carlo 1970-77 For Oldsmobile 442 1964-71 For Oldsmobile Cutlass 1964-77 For Pontiac GTO 1964-73 For Pontiac LeMans 1964-77 For Pontiac Tempest 1964-70Size Chart:Packing size: 52 cm x 34 cm x 22 cm/20.47 inch x 13.39 inch x 8.66 inchPackage Includes:1xBolt On Rear Disc Brake Conversion KitNote:Please allow slightly errors 1-2cm/0.39-0.79inch differences due to manual measurement.