Any HD truck yards around? These things are antiques, so I don't know how many you'll find laying about, but they sold a lot of them, so useable parts may be around....

Try this outfit:

http://www.precisionrebuilders.com/p...ogPWP-0399.pdf

I see the engine & part listed, don't know much else, found it by google search for "ford 401 477 fan hub".