Overheating during idle

Hi,
I have a 71 340 VS Duster and just got it started again after about 7 yrs of sitting. I changed the oil, ran a fuel line to a gas can so I knew it was fresh clean fuel, changed the water pump, lower radiator hose, radiator cap and flushed the cooling system. The car still gets hot when Idel. The water starts flowing well in the radiator at about 185 so I do believe the thermostat is working. I have not put coolant in it since it overheats and spits the water out. Any suggestions?

Thank you