GMPartsGiant.com offers the wholesale prices for genuine 2004 GMC Sierra 1500 2WD parts. Parts like Shield/Engine Splash are shipped directly from authorized GM dealers and backed by the manufacturer's warranty. Parts fit for the following vehicle options. Engine: 6 Cyl 4.3L, 8 Cyl 4.8L, 8 Cyl 5.3L, 8 Cyl 5.3L Flex, 8 Cyl 6.0L. Model Code: 1500 CREW CAB LONG BOX, 1500 CREW CAB STANDARD BOX, 1500 EXTENDED CAB LONG BOX, 1500 EXTENDED CAB STANDARD BOX, 1500 REGULAR CAB LONG BOX, 1500 REGULAR CAB STANDARD BOX.