almost overheating

An actual temperature number would be better. On my 69 Dart, when the gauge hits 3/4, needle covering the "P" on the face of the gauge, the actual temperaure is205 - 210, so I would not worry, but not all gauges are calibrated the same.

Cover the radiator with cardboard while IDLING and put a heat sensor gun on the upper hose near the thermostat to get an idea of the actual temperature.

My normal range is between the "T" and "E" on the gauge, thats equal to 190 - 195 degrees. The 10 - 15 degree temp rise moves the needle quickly across the face of the gauge. I was concerned until I found the actual temperatures.