When we analyze the factory 6-Pack engineering, you could get way better fuel economy from the 6-Pack than you could a 4-Barrel (2 of my Uncles tell me this). I thought about that for quite some time. I reasoned that normal driving only used the center carb. The outer carbs only kicked in with serious foot action. The bores of the primary carbs (I surmise) were smaller than the primaries on the 4-Barrel, creating higher velocity at normal driving range; and thus better atomization of the fuel. When the secondaries kicked in, you got the 1000+ CFM carburetion.
It looks like you are funneling this into a 4-barrel intake manifold. I question how the fuel distribution will work. Don't know, just pondering.