Coolant temp is low because of 3-row stock radiator and shroud.
The moment the thermostat barely opens the occuring coolantflow is enough to drop the engine temps below thermostat rating.
Tried different 'stats. Some had a wider opening temprange and ran the engine temp different, but none could keep it at its designed rating.
But I rather have an engine running too cool then too hot, especially when running on propane.

I know in wintertime the intake air could pretty much reach ambient temps, but that was when I had the temp-sensor located in the airfilter housing.