It would depend on which side of the radiator the external fan is attached to. If the fan is attached to to the engine side, you would want it to pull air (same as waterpump fan), if the fan is in front of the radiator, you'd want to set it up to push air through the radiator. Most electric external fans that are sold are able to push or pull just by reversing polarity. I used a 2000cfm electric fan to push cold air through the radiator of my 1970 Olds 442. This was very effective in controling water temp. while idling on hot summer days. Hope this helped.


