Contrary to overheating, my 1968 302 Ford is running on the cool side(170) down the road. It's in a 1934 Ford with aluminium radiator with shroud. No heater core and using bypass hose from thermo housing to water pump with the other tube plugged. Sound I restrict the bypass hose a little and see if it makes a difference? If I let it idle in barn it will go above 180 .