Just stumbled upon a seller on ebay called "Mad Dog Racing."
http://item.express.ebay.com/Ford-351C-Street-Valves-1970-74-2-bbl-new_W0QQitemZ380054717264QQihZ025QQcmdZExpressItem
And no, I'm not looking at these valves for my engine. I just stumbed upon this seller while browsing.