Vacuum Closes Non-Bypass Heater Valve. Heater Valve. Type: Heater Valves. 1977 Buick Century Submodel: Coupe; Engine: 5.7L V8; 3 Outlets; Right Angle Hose Connection; w/ Threads;. 1977 Buick Century Submodel: Sedan; Engine: 5.7L V8; 3 Outlets; Right Angle Hose Connection; w/ Threads;.
