Overheating after new head gasket

I just changed the head gasket in my Sunfire and now it over heats. The coolant level is fine. I also changed the thermostat but it stll overheats. any ideas?

i replaced my head gasket because of overheating and it didn't work either. i also changed the thermo. and water pump. my heater smells like coolant so I believe it is the heater core. if your's is not smelling like that then try the radiator and hoses.