'67 289 Alternator whine

I've replaced all the underhood wiring (except for the hood mounted turn signals): main loom; engine guage / coil feeds; alternator to main loom; battery cables (upgraded to 0 or 2 guage); ground straps; etc., etc.. New battery, alt (tried two), and voltage regulator.

I'm getting a hell of a whine from two different recently rebuilt alternators. No whine w/ alt drive belt off. No whine w/ leads off alt. Wiring seems correct. Fan blades on case are not rubbing. Suggestions? I suspect wiring but . . . it seems things are connected correctly.