I have a 1967 Chevelle with a BB402 that runs hot in traffic. When the car is moving, the temp is normal...but if I get caught in traffic or try to cruise in heavy traffic flow, the temp rises..and fast...up to almost 240F. I have had to pull over a few times and let it cool down which is becoming annoying. The car has a stock radiator in it. Can anyone give me a suggestion on how I can make my car more cruiser friendly? Thanks