Replacement 4-blade fan. What say you?

[Kube]

So do you have the old pump or old pump shaft ? Try your fan on that, might be easer than finding a known "good" fan right now

Just got an old Ford pump with four blade attached. That assembly feels good and solid. Later tonight, if time allows, I'll see how the Ford fan fits the leakless pump shaft.

 

[Kube]

I have now installed the Ford four blade fan on the leakless pump. Feels good.
So, I'd say the two-blade fan was the main culprit in this fitment issue.

Thanks for all of the advice men.