You need to re-read the description of the fan. The fan has an arrow on the shroud and only flows air in one direction. You do not reverse the blades. The fan is flat on both side, so if you want to mount it as a pusher you would mount it so the other side of the fan was against the front of the radiator with the arrow pointing into the radiator. If you want a puller you mount the other side of the fan to the radiator with the arrow pointing out from the radiator.
I hope that make sense.
