Coolant pressure climbs with pump speed, and a standard thermostat valve can be forced off its calibration once the engine is working hard. This one holds 180 degrees whatever the rpm, and the copper and brass build resists the corrosion that eventually sticks a cheap unit shut.

Mr. Gasket 4364 High Performance Thermostat Features:

• Opens at 180 degrees.
• 2.12 in. diameter.
• Designed to resist large variations of coolant pressure at high rpm.
• Fully opens at the correct temperature consistently regardless of engine rpm.
• Copper and brass construction resists corrosion.
• High flow design.
• For high performance street, drag race and oval track use.