GMPartsGiant.com offers the wholesale prices for genuine 2015 GMC Sierra 2500 HD 2WD parts. Parts like Nameplates 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: 2500 CREW CAB STANDARD BOX, 2500 REGULAR CAB, 2500 REGULAR CAB STANDARD BOX, CREW CAB 2500 LONG BOX, DOUBLE CAB 2500 LONG BOX, DOUBLE CAB 2500 STANDARD BOX.