Can You Help A Girl Out?
Flushing would be my first step. If you havent done it since you have owned the car it its worth it just to get it done. Throw in a new thermostat there cheap enough. My way might not be the same as everyone elses. Get some of that prestone cleaner you add it and let it run for a bit. Then drain keep the water hose to keep it filling till you see clean water coming out. Then ad back in antifreeze till you see the green coming out. This is messy so doing it in the grass is smart and have a big enough bucket to hold the coolant so you dont get that all over. Just keep water in it wont hurt a thing that water wont be in there long enough to cause overheating. Remove thermostat before you do this. 40 year old car needs some love. Oh keep the return line off so its flushing and you can see the crap coming out.