Over heating

Did you purge air out of the system? If all else fails you may be due for a new radiator.

Drain the engine block at the bottom to fully get rid of all the crap. Also need to put in a new radiator with peacock plug so you can flush and drain easier in the future. The radiators are terribly and clog easily. That will fix our heating issues. Also their heater core if neglected are notorious for clogging as well. That is a lot of work though so you probably want to avoid that altogether. Just flush the hell out of the system and drain and reverse flush the heater core to unclog the heater core. You can pour coolant flush into the heater core and let it sit inside the heater core with the heater core hoses plug up so the chemical stays only inside the heater core to work it's magic and unclog all the gunk inside. Then after a few days or at least 24-48 hrs flush the heater core by itself and let it drain into a catch container. That should bust lose all the gunk in there. Then put in new radiator. Also should check that your clutch fan is operating good. If it is failing it could cause your car to overheat. You can google online how to test. It's cheap I would just go ahead and replace it if it is original even if it passes the test. Since you already have everything out and easy to get to why not.