GMPartsGiant.com offers the wholesale prices for genuine 2003 Chevrolet Express 2500 4WD parts. Parts like Wiring Harness/Body 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 4.8L, 8 Cyl 5.3L, 8 Cyl 6.0L. Model Code: 3/4 TON CARGO EXPRESS.