Replaced cylinder heads and head gaskets, but car is still overheating?

97 Ford Taurus, replaced the cylinder head and head gaskets. Car started fine and we let it run for a while before taking it out for a test drive. After about ten minutes the car started to overheat again, coolant came out and steam came from under hood. We also replaced the thermostat. What other possibilities are there?

Check the bottom radiator hose. Make sure that the hose is not collapsing when the engine is reved to higher rpm than idle. This could cause the coolant to overfill the recovery container. It could also be the water pump. The pump could have broken fins on the inside making it less efficent or the impeller could be slipping on the water pump shaft when the engine gets up to operating temperature.

Did you have that head checked for cracks while it was off? Why did you replace the head gasket?

I'd look at the fan if I were you. More like you "should have" looked at the fan.

When was the last time your cooling system was drained, flushed and CLEANED with one part powered acid cooling system cleaner to get the corrosion, rush and slime out? If anyone had EVER dumped discount store antifreeze 1995 or after it will not mix with the factory installed Ford antifreeze. Your cooling system is plugged and it will need to be cleaned.