The Chevrolet Express 6.0 V8 304hp (2001 - 2007) produces 304bhp and 488Nm in standard form. Our Stage 1 ECU tuning file raises output to 325bhp and 515Nm, a gain of 21bhp and 27Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.