5 or 6 blade cooling fan

[WayneShelton]

Ive noticed on line IE ebay and such that they show both a 5 and 6 blade cooling fan.
My question is which one is correct for our 71, 340.

 

[xLURKxDOGx]

Ive noticed on line IE ebay and such that they show both a 5 and 6 blade cooling fan.
My question is which one is correct for our 71, 340.

7 blade clutch fan.

Jake

 

[Wyrmrider]

more blades with less pitch works better
except heavy truck or motorhome
then more blades and more pitch
they take a hd clutch fan