GMPartsGiant.com offers the wholesale prices for genuine 2007 GMC Sierra 2500 HD Classic 2WD parts. Parts like Exhaust 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 5.3L, 8 Cyl 6.0L, 8 Cyl 6.6L Diesel, 8 Cyl 8.1L. Model Code: CLASSIC 2500 CREW CAB LONG BOX, CLASSIC 2500 CREW CAB STANDARD BOX, CLASSIC 2500 EXTENDED CAB LONG BOX, CLASSIC 2500 EXTENDED CAB STANDARD BOX, CLASSIC 2500 REGULAR CAB.