SOLVED!....sort of. Where's there's spark.. there's no fire!

A FORD 1G, 2G, fan.

The 13 blade unit has uniform sharp-tipped blades. They came originally on early Delco 10DN alternators with external voltage regulators. Some knothead complained the early fans did not look High Tech then came up with the usual BS gobblygook about asymetrical being better. If it was better goddamned computer muffin fan blades would be asymetrical. I said it 1,000 times I would have lasted ten minutes in a corporate environment until the SWAT team arrived.