I used a meat thermometer in the radiator once to diagnose a problem. The temperature was normal but the temperature gauge reading was higher than normal. It turned out the probe wasn't long enough on the new temp sensor from Dakota Digital and not enough of it was exposed to the coolant flow. I contacted DD who sent me a longer temp sensor and problem solved.
Thanks for responding. I checked Temps on up rad hose around 166
Lower around 157
Thermostat housing around sending unit around187. Engine gives no indication of being hot but the Guage is at half way . It's is a 52 year old original Guage. Thanks again for the great info and as usual, what are your thoughts on this.