Pusher vs Puller Electric Fan

I read that puller fans are more efficient at cooling your engine than having a pusher fan in front of the radiator.

I bought a SPAL puller fan and shroud that fits my aluminum radiator. Looks great but the fan motor hits the water pump pulley. I need about 1.25" extra clearance. I don't have enough room unless I cut into the radiator support.

Any of you guys using a pusher style electric fan and how is it working for you? Are you using it in combination with a flex/mechanical fan ?

Thanks.