Our NEW Black Out Series 1955-70 Chevy Belair, Impala and Biscayne rear disc brake conversion kits come standard with ratcheting black powder coated GM brake calipers with emergency brake integration, 11″ cross drilled and black zinc caotedbrake rotors and high quality caliper mounting brackets. When converting to rear disc brakes, make sure to use a 4 wheel disc proportioning valve.