GMPartsGiant.com offers the wholesale prices for genuine 2004 Chevrolet Express 2500 2WD parts. Parts like Engine Assembly-Cylinder Head & Related Parts 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, 3/4 TON PASSENGER EXPRESS.