Hello! Hope all is well. Can anyone tell me the correct name for this connection on the top of the engine? I believe it is pumping coolant into the block. It is right in the middle of the photo, to the left of the coil. Thanks in advance, my friends.

 

Heater control valve

 

Thanks a bunch, vmathy. Much appreciated.

 

Don't know which year you have. In 1966 the Olds parts book referred to it as "valve assembly" (group 8.848), but as was mentioned, most would likely call it "heater control valve" or simply "heater valve".

 

Thank you, Ozzie. You nailed the year. It's a 1966 Dynamic 88. I appreciate your guidance.

 

Since we now know the year and model, we can also get the GM part number.
If it has the "manual" A/C (option C60) the part number is 389096.
If it has the "auto" A/C (option C61) the part number is 390380.

 

The difference is that the valves for the C61 automatic A/C had a provision for a temp sensor to thread into the top of the valve.

 

Joe and Ozzie, I really appreciate your incredible knowledge. Thanks a million. Do you know a good source for either of these parts? I'm having some difficulty finding anything...other than this item on Ebay for $250: http://www.ebay.com/itm/NOS-GM-1964-...440598&vxp=mtr

 

I'm sorry, but I'm having difficulty understanding how you can't find a replacement. They are everywhere. RockAuto has them for $30. I ASSUME you need the one for manual A/C. The one for the C61 automatic system is difficult to find and will be expensive. You still haven't told us which system you have. It's hard to help without complete information about your car.

 

Joe, listen, I'm new to all this, so I'm probably just searching by the wrong part number or something. It's easy to do, especially with a part that goes by multiple names. My car is a 1966 Dynamic 88, with the 2 barrel 427 7 liter. How would I know whether I have "auto" or "manual" a/c? My car did come with a/c from the factory.

 

If you search for the original GM part number, you will typically only get results for very expensive original parts. Aftermarket vendors make replacement parts. Search for a "heater control valve" for your car. NAPA, RockAuto, Advance Auto Parts, Autozone, Oreilly's, whatever your favorite source.

Olds had two A/C types available on your car, the manual one where you set a slider between HOT and COLD on the control panel and an automatic one where you set a dial with the temp you wanted.

FYI, your engine is a 425, not a 427.