Reply to "Ron (accobra) & all, another interesting intake manifold"

Vacuum from one port is enough for the PB.
If you are already drilled string the ports together with tee fittings like one would do with a fuel line, on the outside of the manifold.
The picture you show of the block is for nitrous more then anything else.
You don't want the plumbing in the center. It will be in the way of everything and will have no accessabilaty once installed on the car.
The cleveland throttle pivot will be further forward then this manifold is and will pull on the center pivot arm on the drives side.
Keep the throttle arms to the carbs to the passenger side of the pivot arm and anchor both at the same point. Keep those arms as horizontal as you can at throttle rest.
I used a tower to do that to the drivers side. Everyones linkage will be a little different.
Why don't you just buy a Pantera linkage set from a vendor as a starting point?