Why does my 1965 Mercury Comet overheat perpetually?

I drive a 1965 mercury comet with a Ford 127 HP online six. I replaced the radiator and the water pump, and put in a thermostat, but the thermosat is for racing and is rated for 180 F, my engine is supposed to have 160 F. Any given time I'm driving my car runs dangerously hot/overheats after about 1/2 and radiator fluid levels are normal, no leaks. Could the thermostat be the issue?

Genesis 3:17

Who knows how much crud has accumulated inside the water passages in the block in 52 years!

I doubt the thermostat is the problem. Normal operating temp is about 200 F.

You may need to flush the cooling system. I've had good results doing a "freeway flush" using Prestone Radiator Flush + Cleaner.

A "freeway flush" means driving the car for about 3 days and 100 miles. You need a flush product that can stay in the system that long. If the system has not been flushed for a while, it may take more than one flush.

Also, used distilled water for flushing. Tap water can leave mineral deposits in the system.

JJ and Huggy seem to have the right idea, I'd just ask if you put the t'stat in the right way. Remember it points away from the engine.

Overheating is cause by a lack of circulation. Find that and fix it.

Start with the basics. The water pump on that vehicle is driven by a belt. Make sure the belt is in good condition and is tight,

Check the fan to be sure the blades are not damaged or bent out of shape, If the fan blades are flattened out, they will not move enough air to cool the radiator.

Have the freeze plugs been replaced? Sometimes people who are not really qualified to do mechanical work will install an new freeze plug over the old one, rather than removing the old one, and this causes an obstruction in the engine water jacket

Look for obstructions that can be blocking the airflow. Something as simple as a plastic bag melted against the radiator can cause overheating.

Try the 160 degree thermostat. If the radiator fan is belt driven the fan clutch may be bad.
Is the shroud still on the radiator? If someone took ir off the air flow isn't being directed properly and can also cause the motor to run hotter.

Knowing exactly when it overheats would help. Local traffic, constant 55 cruising down the road, faster if idling in drive at stop lights, etc.Running lean can cause excessive heat as well. Ever rebuild the carb? Jets could be restricted.

" rated for 180 F, my engine is supposed to have 160 F"
"Could the thermostat be the issue?"
You think? Sherlock Holmes should watch his back. You're dynamite.

Old car and hot thermostat that'd match