GMPartsGiant.com offers the wholesale prices for genuine 2018 Chevrolet Express 2500 parts. Parts like Backup Alarm are shipped directly from authorized GM dealers and backed by the manufacturer's warranty. Parts fit for the following vehicle options. Engine: 4 Cyl 2.8L Diesel, 6 Cyl 4.3L, 8 Cyl 6.0L, 8 Cyl 6.0L Flex. Model Code: 3/4 TON CARGO EXPRESS, 3/4 TON PASSENGER EXPRESS.