Mr. Gasket Thermostat - 180 Degree

Designed to open at 180 degrees every time, regardless of engine rpm, and it's high-flow design and brass and copper construction eliminate the damaging effects of cycling when you're stuck in stop-and-go traffic. It includes the rubber gasket and has a pressure relief valve.
This thermostat is compatible with most 2004-2008 LS based engines except for 2007-up new chassis CK trucks and SUVs which had a new design water pump that uses a slightly taller thermostat. You can identify the new style thermostat by gasket diameter of 2.34 inch, the earlier style is 2.28 inch.