High Performance / High Flow Thermostat 160 Degree Fits 1955-1978 Chrysler, Dodge, Plymouth V8 Mr GasketMr. Gasket High Performance Thermostats are designed to resist large variations of coolant pressure at high RPM (revolutions per minute). This allows them to fully open at correct temperature consistently regardless of engine RPM. The design also provides the high flow that engines operated a higher RPM need. This thermostat also features a copper brass construction to further resist corrosion. Mr. Gasket High Performance High Flow Thermostats are