GMPartsGiant.com offers the wholesale prices for genuine 1999 GMC K3500 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 5.7L, 8 Cyl 6.5L Diesel, 8 Cyl 7.4L. Model Code: K3500 CAB CHASSIS 135.5, K3500 CAB CHASSIS 159.9, K3500 CREW CAB LONG WHEELBASE, K3500 CREW CAB SHORT WHEELBASE, K3500 EXTENDED CAB, K3500 REGULAR CAB.