GMPartsGiant.com offers the wholesale prices for genuine 2007 GMC Sierra 2500 HD Classic 4WD parts. Parts like Brake Lines/Rear 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.