Overheating issue

Is the radiator fan turning on? If it is dead, the engine will not overheat at highway speed when natural air flow is sufficient.

That suggests there was a problem that was not properly diagnosed. Running a radiator fan motor continuously will shorten its life quite a bit, so again, be sure it is turning on. If you can hear it with the window open, we can move on.

Feel the upper radiator hose after the engine has warmed up. It should be too hot to hold onto for very long. If it is, feel across the front of the radiator to see if there is cold areas. That would indicate it is partially plugged. Also, observe if the cooling fins crumble easily, like a rotten chocolate chip cookie. That will greatly reduce its ability to give up its heat to the air. The clue is the lower hose will also be too hot to hold onto.

If the upper hose is not real hot, you may need to bleed the air out of the system after it was opened for other repairs. Look for a bleeder screw on the thermostat housing. If there is none, there will be a threaded plug or a temperature sensor on or near that housing that can be removed while the system is being filled. If you need to unplug the two-wire coolant temperature sensor to remove it, do that with the ignition switch off to prevent setting a diagnostic fault code that could confuse someone later.