I have a freind who is machining and selling these He makes them in limited quantities. They are available on EBAY . Here is the link. Thought you guys might like them.
eBay Motors: Buick Grand National Vacuum Block with 1/8” NPT ports (item 200175638085 end time Nov-25-07 18:50:27 PST)

eBay Motors: Buick Grand National Vacuum Block with 1/8” NPT ports (item 200175638085 end time Nov-25-07 18:50:27 PST)