Why is my 5.0 F-150 overheating?

Beachco i have been trying to come up with specifics on what could be wrong with your F150 but I'm having no luck. I'm going to refer you to a site that has a list of items to troubleshoot if your engine is overheating. http://www.aa1car.com/library/overheat.htm

Check for possible Cat.Converter restriction.If so,O2 sensor sends errant signal to computer which then leans out a/f mixture,causeing increase of operating temp. Also, continued operation w/exaust back pressure will inhibit proper valve function. If your lucky the engine will stall out.If not, unignighted fuel will get to the converter(now red hot).Wanna take a wild guess what happens next?

you could still have air in system or you need to wait for the thermostat to open

make sure that the thermostat didnt slip out of place when you installed it, also try bleeding the air out of the system multiple time

Ford has a very high heater core like farther above the engine than it should it's much harder than regular vehicles to bleed the heater core for air bubble you'll still get heat but you'll still have a bubble

Make sure to have the heater on when you go to bleed it keep the throttle down to 2500 RPMs or just a low-rev cuz I know it doesn't have a gauge for that