1968 Barracuda. Is this the stock radiator?

Do not trust the factory gauges!
Get an IR gun and shoot the stat house.

If you're concerned, take the stat out. Take an old stat apart and put the washer part back in. Hit the road and see what the gauge says, but back it up with the IR gun.
Do not leave it like this. Put the stat, or a stat, back in there asap.