GMPartsGiant.com offers the wholesale prices for genuine 2018 Chevrolet Silverado 2500 HD 4WD parts. Parts like Brake Electrical System 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, CREW CAB 2500 LONG BOX, DOUBLE CAB 2500 LONG BOX, DOUBLE CAB 2500 STANDARD BOX.