I build engines and one thing I have noticed over the years...almost every engine has a mind of its own. Most engines need to be "burped" if any thing is done such as replacing a radiator, hose, or thermostat. By burping I mean that an air pocket can get trapped inside the block and it has to be forced out. There are systems to do this but for the shade tree mechanic, running the front wheels up on a ramp and running the car while watching the gauge will often get the air out. Here is something to consider. Take a real good look at the fins of the radiator and make sure they a free of bugs, leaves, dirt, and debris. You can have a good radiator, coolant system free of air, a good set of hoses, clamps, thermostat, heater hoses, heater core and still run hot if the radiator fins are not free of debris.
Hope this helps