Our 13″ disc brake conversion kit foryour 1964-72 Pontiac GTO, LeMans and Tempestmuscle car will really improve your stopping performance. This Big Brake kit utilizes C4 Corvette 13″ rotors and dual piston aluminum PBR style calipers with 38mm pistons, T6061 aluminum hubs and comes standard with drilled, slotted and zinc plated rotors. Improves 60-0 mph stopping distances and driver feedback.