The Chevrolet Express 6.6 V8 250hp (2001 - 2007) produces 250bhp and 624Nm in standard form. Our Stage 1 ECU tuning file raises output to 280bhp and 660Nm, a gain of 30bhp and 36Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.