GMPartsGiant.com offers the wholesale prices for genuine 1999 GMC C2500 parts. Parts like Heat Shields/Exhaust are shipped directly from authorized GM dealers and backed by the manufacturer's warranty. Parts fit for the following vehicle options. Engine: 8 Cyl 5.0L, 8 Cyl 5.7L, 8 Cyl 6.5L Diesel, 8 Cyl 7.4L. Model Code: C2500 CREW CAB, C2500 EXTENDED CAB LONG BOX, C2500 REGULAR CAB.