Has anyone changed fan blade type on your engines to get better cooling? any impacts on water pump life?

I have 3 fans to chose from...the first is a 4 blade fan with smallish blades (std one from LMC - car application?), the second is a 5 blade fan with irregular fan blade spacing, and the 3rd is the same a 2 but slightly wider blades and have a "lip" or turnup at the end.. all were removed from misc chevy/gmc trucks over the years...

would you know which is correct for a 1960 261? would changing to a 5 blade fan provide better cooling at low speeds?


Old Truck addict
1950 chevy 1 ton napco
1956 gmc 1 ton dually napco
1954 chevy 3/4 ton napco
1957 gmc civil defense napco panel