I have the same problem on a 2000 model ford F150.

 

Hey man, I had a similar problem in a 5.0 coupe I did everything to it and it still ran hot and would occasionally over heat. It had a 3 row radiator in it. I was just about to give up and sell it, and I saw a nice two row radiator "what they came factory with" I decided for 40.00 it was worth one last shot. I changed them and that was all the problem. My radiator had something hit it in the front a bend the fins and it was getting proper air flow. I couldnt see it because of the core support. I changed the thermostat flushed the system, new water pump, changed the electric fan out for a stocker and still the same thing. I would check that radiator.

 

I'm having same issues with my 2001 ford f150 4.2 engine v6 I change thermostat, water pump, fan clutch , and still the same it heats up only went I turn on my AC can someone help me please