For use with OEM 1977 – 1991.5 Chevrolet Kingpin knuckles. Includes 5/16" thick 7075 aluminum caliper mounting brackets, aluminum brake hats that are drilled to accept 5/8" drive studs in a 6-1/2" x 8-bolt pattern, solid steel rotors with cleaning grooves, slot-drive rotor attachment system, all required mounting hardware, and MW 4 piston calipers with linings. Installation - Service instructions can be found on Service Bulletin #0112.