eastwildlife

Usually if the caps good, which raises boiling temp of coolant, but it still overheats under load it's because it can't shed the heat. Most fans electric or thermostatically controlled pretty much loaf at highway speeds. If running around town she's fine or unloaded, I'd take a better look at your radiator. Solder bloom may be the culprit. Remote possibility, but based on her age and perhaps lack of coolant service, it may be the fins on the water pump have rusted away. I'd Imagine you've ruled out head gaskets which these engines are not know for. Radiator still sounds most likely.