I just bought a 1964 chrysler newport with a 361 big block and 383 heads from what I am told. The car runs hot and I have no idea if it is just the radiator or if something was not done when the 383 heads were put on. The radiator has been flushed and does not appear to be leaking. If anyone has any information it would be greatly appriciated. This is my first mopar, I have been around GM my whole life so I am not familiar with mopar.
invest in a 30 to 40 buck infrared temp gun... so you know exactly how hot the parts are around the cooling system . thats the ONLY way to know for sure...210 to 230 really is NOT hot with a proper mix of coolant to water .. with a properly selected thermostat.. the fan clutch working properly.. if equipped with a fan clutch..hot engine lights generally don't come on until 245 to 260F.. 50% coolant to 50% water or the even better blend of 70% coolant to 30% water is needed in most cooling systems now.. does your radiator cap hold pressure..???? not all do.. squeeze an upper hose.. do you have a coolant recovery tank now.. all the caps are designed to use coolant recovery tanks.... will the cooling fan hold a shop rag against the front of the radiator core with the engine idling..???if you have a fan clutch.. does it cycle on and off then back on as the thermostat cycles..what temp thermostat do you have installed...does your engine have some kind of a bypass hose... where the coolant flow blocked by the closed thermostat is allowed to circulate into the water pump where it gets send through the block and heads again and again until it picks up enough temp to open the thermostat.. so it can swap the hot coolant in the engine with the cooler coolant in the radiator.. this closes the thermostat so the coolant in the radiator can stop so the fan has a chance of taking the heat out..lastly... does it only overheat when driving at freeway speeds or heading up long grades...if so.. please do a cold engine full flow fuel pump test for 15 seconds into a clear plastic bottle.. to verify the fuel system can feed the carb with enough fuel to stop it from leaning out when you ask for more horsepower..i can give you exact instructions on the full flow fuel pump test.. this has found a lot of problems..