you need to double check your coolant level, last nite when i changed my intake manifold gasket i had to drain the radiator, i filled that bitch up and squeezed all the air out if it that i could, drove the car around and it was running about 210 degrees which is about 30 degrees higher tha norm, turned the heat on and it went down, went back to the house, let it cool down and ended up putting another half a gallon of coolant in the car, filling the radiator and squeezing as much as you can its still hard as hell to get the coolant to the head, but now its running at around 160-180 again.........