I never heard of factory hood pins. If there is such a thing I feel kinda dumb, as I have never heard of them...

"NOS GM Hood Pin Auction" (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2437795358&category=34204)

Does anyone know for sure?

No first generation factory hoods came with pins.

I think 69 cross ram hoods had pins, but that was available as a regular production option. The pin in this auctin could be NOS meaning it was bought from GM, and never installed.