My 65 289 HiPo runs well, but engine temp seems a bit high even though gauge indicates lower half to center of arc. After a 15 minute or so drive, using an infared thermometer pointed at thermostat housing bolts, side of water pump and top orf radiator next to cap, temps run around 200 degrees, plus or minus 10. I just replaced the 180 degree thermostat, flushed the radiator and added new coolant along with water wetter. No change in temps. As info, my car has no heater. Are my temps normal or high?