My diligence may have payed off... these pictures show plenty of detail. I am going to post pictures and links here in hopes that it may help someone else in the future.
The thread these pictures are from can be found here:
http://forums.corvetteforum.com/c3-t...ng.html?nojs=1
Courtesy of the Corvette Forums.
It appears the connection on the back of the carburetor goes to the brake booster. And the manifold supplies vacuum for the A/C and shift modulator. Also in the photos are the connections for PCV and the vacuum advance.