GMPartsGiant.com offers the wholesale prices for genuine 2014 GMC Sierra 2500 HD 2WD parts. Parts like Engine Block Heater are shipped directly from authorized GM dealers and backed by the manufacturer's warranty. Parts fit for the following vehicle options. Engine: 8 Cyl 6.0L, 8 Cyl 6.0L Flex, 8 Cyl 6.6L Diesel. Model Code: CREW CAB 6'6" BOX 3/4 TON, CREW CAB 8' BOX 3/4 TON, REGULAR CAB 3/4 TON.