Classic/Antique Car Repair: overheating, oldsmobile omega, heat transfer properties

Question
i have a 1974 oldsmobile omega with a v8 5.7L and in low temp weather it runs great but in the heat it overheats the tstat is good the water pump is good i was told to change the radiator what else can i try before spending 200 on the radiator

Answer
Dyron, I'm afraid that if it was anything else it would overheat regardless of outside temperature. It is probably a safe bet that the radiator tubes have built up a layer of crud that stops the flow of coolant and reduced the heat transfer properties.
Brad