The Chevrolet Silverado 6.6 V8 397hp (2007 - 2014) produces 397bhp and 1037Nm in standard form. Our Stage 1 ECU tuning file raises output to 440bhp and 1100Nm, a gain of 43bhp and 63Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.