At what temperature is 1960 Cadillac 390 motor overheating?

A 1960 Cadillac 390 engine, like most cars of that era, will typically overheat when the coolant temperature exceeds 220-240°F (104-116°C). However, the exact temperature at which it overheats can vary slightly depending on factors like the condition of the cooling system (radiator, hoses, thermostat, water pump), ambient temperature, and driving conditions. The car likely had a temperature gauge that would indicate overheating before that temperature is reached. If the gauge shows the engine is getting dangerously hot, that is a clear signal of an overheating condition.