GMPartsGiant.com offers the wholesale prices for genuine 1998 GMC K1500 parts. Parts like Spark Plug Wiring are shipped directly from authorized GM dealers and backed by the manufacturer's warranty. Parts fit for the following vehicle options. Engine: 6 Cyl 4.3L, 8 Cyl 5.0L, 8 Cyl 5.7L, 8 Cyl 6.5L Diesel. Model Code: K1500 EXTENDED CAB LONG BOX, K1500 EXTENDED CAB STANDARD BOX, K1500 REGULAR CAB LONG BOX, K1500 REGULAR CAB STANDARD BOX.