The GMC Savana 5.7 V8 255hp (2003 ->) produces 255bhp and 447Nm in standard form. Our Stage 1 ECU tuning file raises output to 275bhp and 470Nm, a gain of 20bhp and 23Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.