When you need a reliable thermostat for your Duramax 6.6L V8 vehicle from 2001 to 2019, the AcDelco 131-131 Rear 180 Degree Thermostat is the perfect choice. With its offset design and built-in bleeder valves, this thermostat ensures complete and efficient heat control at all times. This state-of-the-art thermostat offers up to 180 degrees of heat flow, which makes it the ideal choice for high performance engines. It has been rigorously tested to ensure that it meets the highest quality and performance standards, so you can be sure of reliability day in and day out. When searching for quality and dependability in a thermostat, look no further than the AcDelco 131-131 Rear 180 Degree Thermostat - the only choice that gives you total control of your engine's temperature!