Justin:
With regards to your intake manifold, below are some excerpts from the CVAR rulebook regarding carburation and manifolding. The first two pertain to the general production car rules:
"Intake manifolds must be OEM, period aftermarket, or aftermarket of period design. For V-8 cars, aftermarket manifolds must be of period design, non-air gap, and dual plane."
"Production cars may upgrade to bigger versions of their original carburetors or replace them with Webers with the same number of barrels, (i.e. Midget with a single Weber in place of two SU’s)."
Basically, this means that the Group 2 cars are eligible to run Webers, but can only have the same number of venturis as the car came with from the factory. In other words, no dual twin-throat Webers as you eluded to in an earlier post. Some of the other vintage groups will let you get away with that, but CVAR will not.
The next excerpt is from the same rulebook, only it pertains strictly to all participants in Group 4:
"Carburetors must be of original manufacturer and number. Internal engine/gearbox parts are restricted to 1972 SCCA GCR and PCS regulations."
In other words, in your case, no Webers allowed at all. I ran the stock carbs on my car with the choke flaps removed and low-restriction air cleaners. I also polished the intake runners and matched the ports to the head. I'm sure that they still didn't flow like a set of Webers, but that was the best I could do within the rules. The car still ran like gangbusters, though.
I PM'd you a link to CVAR's website. You will find all the rules spelled out for you right there.