Performance Online now offers you the option of upgrading the rear of your muscle or classic car and to 12″ diameter rear disc brakes. This rear disc brake conversionis designed to fit the popular GM 10 and 12 bolt rearend. These kits come standard with aluminum PBR Calipers, Zinc plated drilled & slotted rotors and stainless brake hoses. Calipers have energency brakes integrated for your safety.