[Bob Bidonde]

You are running with the GAV open way too much! If the engine is running correctly, the GAV should be 1/8th to 1/4 turn open for normal running at operating temperature.
I have a temperature sensor in the upper radiator hose just below a 160F thermostat and the gauge normally registers steady at 160F while cruising. On an exceptionally hot day (100F), the operating temperature registers 180F.