2001 – 2006 Gmc Sierra 1500 6 Lug Models with Single Piston Rear Calipers & 3/4″ Thick Rear Rotors. 1999 – 2000 Gmc Sierra 1500 Rear Disc Models. 2001 – 2006 Chevrolet Silverado 1500 6 Lug Models with Single Piston Rear Calipers & 3/4″ Thick Rear Rotors.