Quote: The 5 blade pictured looks like the Mopar Performance unit that I have run on my 67 GTX in Arizona with no problems.
That 5 blade pictured looks like a broken seven blade fan. That thing could not possibly be balanced.
Looks sort of funny but that's how they are made. Apparantly uneven spacing prevents annoying resonance (noise and stress). The pair of two blades is close together vs the group of 3 that's spread out so it does balance.
