Ok this pos single cam keeps overheating...

I have bled the air out.

replaced the thermostat.

there are no leaks.

allways full of coolant.

fan is wired in with the ignition so its allways running.

It will sit for a long time and be fine...and for the first 30 mins you drive it or so its fine...as long as the rpms are up it stays cool but if Im at a red light or stuck in traffic it gets hot and climbs quickly into the red. but id I rev it up sitting there it starts to lower it
So I figure its not circulating or I still have air in the system...any sugjestions?

Should I change the water pump?