as fitzwilly said, the water pump rotation is suspect. I would assemble the following information:
1. What is the water pump direction (was it intended for a belt system or a serpentine system?)
2. What direction is it turning now?
3. What kind of fan shroud seal do you have? Is there gaps between the shroud and the radiator? Does the shroud cover the entire radiator? Is the fan on the back side of the radiator?
4. Have the pulley ratios been changed?
5. Put a piece of paper in front of the radiator with the engine idling. Does the paper suck to the radiator or blow off? (this tells you if the fan is turning the correct direction)
6. Have you changed the thermostat? Is it oriented correctly? Have you tried it without a thermostat?
7. Did you observe the lower radiator hose when the engine is getting hot? Did the hose collapse?

mike in tucson