What temperature thermostat are you running? I would think you want at least a 180* stat to keep the engine up to a safe operating temperature. If you allow the engine is running below 160* you run the rick of accelerating engine wear because the clearances are to tight.
Get a Infrared Laser Temperature Sensor (they're cheap and a good tool to have), then take a few readings on the block and radiator, that will tell the story.
https://www.amazon.com/Thermometer-SOVARCATE-Temperature-58%C2%B0F-1112%C2%B0F-Refrigerator/dp/B0878WB6HQ/ref=zg_bs_9931459011_6?_encoding=UTF8&psc=1&refRID=1P29GM4J708SKR9ZDAFD
Mike B
