'66 Valiant Running Hotter than Expected

Jim, you are assuming your factory gauge is accurate. That is not a safe assumption. You may or may not actually have a problem, and you can't know for sure until you determine what your actual running temperature is.

JMHO
Already mentioned this to him post #37, along with some others. Sometimes I wonder why I even try on this site.

You can lead a horse to water, but you can't make him drink.
I mentioned that in post #4 and there was no definitive answer and again in post #16. Looking at a gauge with no numbers is like telling me your oil pressure is low while staring at the oil pressure light that isn't lit. I'm out.