Help with proper ID of thermostat &amp; type. I hve one from the auto parts store and Im not sure if it is right because it has extra part. Tractor overheats but when I shut it off before it overheats water gushes out of the radiator non pressureized system. And old tstat opens in heated water. any help would be appreciated. Im restoreing the old girl. It was grandpas old tractor and they fought it for years.