Help picking radiator/fan for 440

Bewy said
Your w/pump pulley needs to be smaller than the crank pulley, to overdrive the pump, it makes a BIG difference. If not, you are wasting your time & money....

Also, the pump. Are the impeller blades enclosed front & rear? I have knocked off 20* of temp on a pump that had one side open.

Crank pulley-6 3/8”
Water pump pulley-5 3/8”

Not sure what you mean if the impeller blades are enclosed front and rear? It’s a brand new 440 source pump.