Where is the thermostat on a 1931 A model ford?

The 1931 Model A Ford did not have a thermostat. Instead, it used a combination of a radiator shutter and a bypass valve to regulate the engine's temperature. The radiator shutter was located in front of the radiator and could be opened or closed to control the amount of air flowing through the radiator. The bypass valve was located in the engine block and allowed hot water to bypass the radiator when the engine was cold. This allowed the engine to warm up quickly without overheating.