The Chevrolet Express 4.8 V8 279hp (2008 - 2014) produces 279bhp and 400Nm in standard form. Our Stage 1 ECU tuning file raises output to 300bhp and 430Nm, a gain of 21bhp and 30Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.