I scanned through this thread and didn’t notice whether you replaced the thermostat. Did you? If not, do it, and make sure you put it in right side up. And replace the gaskets when you do the job. Then refill the system and let it idle, with the heater on and the radiator cap off, and add coolant as the level goes down in the radiator. It takes a while.
yes, because of overheating issue, I replaced the thermostat about a year or so ago…thought that may have been problem…