The GMC Sierra 4.3 V6 285hp (2014 - 2016) produces 285bhp and 413Nm in standard form. Our Stage 1 ECU tuning file raises output to 305bhp and 440Nm, a gain of 20bhp and 27Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.