Manifold

To realize the benefits of multiple carburetion you'll need a special dual or compound manifolds. The main function of a manifold, aside from supporting several carburetors, is to distribute the fuel more evenly by equalizing the distances the fuel-air mixture must flow through the ports to the combustion chambers. The shorter and wider these passages are, the more efficient your engine will be.

Dual and triple manifolds are very effective with gasoline-benzol fuels. The four carb manifold is most effective on engines of very large displacement and particulary with alcohol fuels which require greater flow than gasoline.

For maximum top rpm, be sure that the manifold is large enough to handle the capacity of your engine. one of the first restrictions to rpm is the fuel drag of small, long passages which cause the inside atmospheric pressure to be as low as 12.7 compared to normal outside atmospheric pressure of 14.7 lbs. per sq. in.

Manifold Makes

Almquist
Crower
Cyclone
D & S
Detroit Racing
Drag Star
Edelbrock
Evans
Harper
Harrel
McGurk
Meyer
Navarro
Offenhauser
Sharp
Tattersfield
Thickfield
Thickstun
Weiand

Sources

Fawcett Book 156 How to Build Hot Rods