Check your timing. Timing advanced to much can cause an engine to run hot. Good luck
I`m not meaning the thermostat installed backwards, but if the gasket is on the wrong side of the thermostat, it will not open as it should.
Had similar issues with an older Camaro of mine. Mounted an oil cooler and it ran much cooler
Did you ever figure out what caused it?
Good news update…I removed the 20 inch two core radiator and replaced it with a 24 inch three core radiator. I have drove the cougar around town and on the freeway. The temperature gage got to about the 1/3 range and stayed there. My engine overheating problem is solved. Thanks to Don Rush and West Coast Classic Cougar for getting me all the parts.
Thanks for posting that. People learn a lot from these threads when the solution and the problem are put together.
I was reading this thread to find out if there was anything different from my situation. Moving from the single row to a newer 3 row radiator also resolved my overheating issues. Don Rush saved my car as well!