^ yes, ^ yes, and ^ yes .... still, removing the thermostat will not
cure overheating - and might help with diagnosis only by indicating the thermostat is or is not the problem [and yes Bart, having started life trying to keep flathead Fords cool in the AZ desert I remember those
bags well 
]
note that "overheating" is referring to the
coolant temperature - in a running engine there is a tremendous amount of heat being generated by massive contained explosions of fossil fuels along with the resultant friction [particularly if the lubricating oil is cold or too hot], that heat is what's being transferred to the coolant and then to the atmosphere by the radiator .... if the coolant is not getting to design temperature [measured by the probe in the engine],
where is all that generated heat going? is it being whisked away through the 3 steps of heat transfer so fast it can't be measured? is it magically not heating the engine metal? is it being "air cooled" away?
maybe someone should experiment: with a system that's cooling properly, bring it up to operating temp and check various points on the engine with a good laser thermometer, including the top and bottom of the rad - remove the stat and repeat, checking for any differences in temperatures in the same locations
Bill
