I am using both ports (one on each side of the thermostat) on the intake manifold. The driver side port has the temp gauge sender and passenger side has the thermocouple that activates the electric fans.

If using the 180 degree thermocouple as a guide then the temp gauge is close. The first time I saw the fans kick on the temp gauge said 190. But then as the car sat there idleing the gauge seemed to read more accurate. By that I mean the fans would bring the temp down to where they turn off, then heat would build and they would turn on. I could see all that on the gauge.

I agree that this is a phantom dragon. After I try this electric water pump I am out of ideas. I have adjusted the carb. Maybe I should get the original AC spark plugs?