James J

Hi- I ordered a heater valve for an Edelbrock Performer 2711 manifold and it came in the wrong size-
Can anyone advise me on the correct part for this? And the correct thermostat housing as well- Thanks Jackson

Fun71

Hmm. You don't order a heater valve based on the intake manifold, you order it based on the year of the vehicle. One style valve is normally open and takes vacuum to close, and the other is normally closed and takes vacuum to open.

The threaded fitting is different size on the two versions so they fit the OEM intake manifold. The aftermarket manifolds are made as a one-fits-all and therefore have the larger opening. If you need to use the smaller valve, then you use a reducer in the manifold port.

So what year/model vehicle are you working with?

Easy to determine which valve you need it to have the engine running, turn the dash control to COOL, and check the vacuum at the hose for the heater valve. Then move the control to WARM and check the vacuum at the those. This will tell you if you need a normally open or a normally closed heater valve.

joe_padavano

The more important question is, what is the year and model of the car? Olds changed from normally-closed to normally-open heater valves in the early 1970s, but the timing of the change varied by model line. A-body cars changed in 1973, full size cars and Toro in 1971. If you have the wrong valve, your heat won't work.