We ran a big flat washer instead of a thermostat on the race engines and varied the size of the hole in it to control the temp we wanted the engine to run. If the radiator is efficient enough it will over-cool without some type of flow restrictor. I can look at the wear pattern on the piston skirts of a high mileage street engine and tell whether or not it has been run with a thermostat installed.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!