A 165 opens sooner than a 180 degree thermostat. None of this alters the top running temperature.
In other words, an engine with a 165 degree thermostat will run at the same maximum temperature as one with a 180 thermostat.
If this is so, what is the advantage of a 165 degree thermostat? Maybe the heater will start heating the cab sooner...

1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission