Did you still need help?
What kind of diagnostic equipment do you have?
Ok.. does the heater put out good heat when the engine is starting to overheat?
Does the electric fan come on when the engine starts to overheat?
If there are no air pockets in the cooling system, then the only two things left would be a plugged radiator or a blown head gasket.
Did you have any further questions?
I can give you more ideas if you would like.