Milodon Water Outlet Restrictor
Suit Chevy (All) and Ford (All except pre 67, 390-428)

These High Flow Thermostats greatly aid the proper functioning of a high performance cooling system. They are engineered to warm the engine to a proper operating temperature without making it run hot enough to lose power. Also the "Balanced Sleeve" design is highly recommended for use with High Volume water pumps. With other thermostat designs, the increased flow generated by High Volume water pumps can actually attempt to hold the thermostat closed. The "Balanced Sleeve" design equals the pressure exerted on the thermostat allowing its operation to be solely regulated by coolant temperature.