Ditch the Thermostat?

You don't even need a fan or shroud at highway speed and you are getting hot at that speed. Have you hooked up a real mechanical gauge so you can tell what the actual temp is?

It may not be running hot at all. Are only using a 40+ year old gauge as your reference?

I have not. When I got the car it had a spare instrument console. When I changed the gauges it read the exact same reading. The reading stays firm at the almost furthest right mark but when I've tested the gauge by grounding it out it goes further to the right. While driving it stays within one or two "hash marks" of the constant reading.

Wait, a thought, would Teflon tape restrict the grounding of a sensor and give false readings?