Overcooling on stock set up?

[jondee86]

From what you are describing, it seems that your cooling system is
functioning normally. If the thermostat is working, by definition, it does
not open until the coolant in the engine reaches 80+/- deg, and the
thermostat then modulates to keep the engine at 80 deg.

It doesn't really matter how big your radiator is, or in what condition. The
engine temp hits 80 deg and stays there until the heat generated by the
engine exceeds the amount of heat the radiator can dissipate to the air.

The factory gauge sensor should be located to measure the temperature
of the coolant circulating around the engine. This should remain constant
under normal driving conditions. The aftermarket gauge is measuring the
temperature of the water being sent to the radiator, which will vary.

So try this... find a piece of cardboard and temporarily block off half of
your radiator i.e. the right half or the left half. Go for a drive and see how
the gauge reacts. Watch the factory gauge for signs of overheating !!!!

Cheers... jondee86