Curt, .....The problem with duals on stovebolts is that people put two of the same carburetor that was working well as a single setup, and expect them to work. Too much airflow, not enough venturi velocity, so the things go from WAAAAY too lean to super-rich as the power valves open up. There's a right way to make a dual-carb setup work, but nobody's interested in doing it that way- - - -they'd rather gripe and complain, and spend lots of time tinkering with a system that can only be mediocre, at the very best.
Jerry
Jerry, the same problem exists with most engines. Many enthusiasts try to buy carburetors to match the manifolds. When the manifolds were sold new; the guy that purchased a dual one barrel manifold for his stovebolt ALSO purchased a dual point distributor, a set of domed high compression pistons, a 3/4 or full race camshaft, headers, and a higher numerically rear end gear. Many don't even stop to look at factory examples. When Chevrolet offered the dual quad engines for the 283 the single quad engine used a carb of approximately 485 CFM. The dual quad engines got a bigger cam, better exhaust, yada, yada, yada BUT TWO CARBURETORS THAT WERE APPROXIMATELY 415 CFM! NOT 2 of the 485 CFM single units. Same is true with your sports car examples. The big Healy used a pair of H-6 carbs, but when they upgraded to 3 carbs, they used H-4's.
But as always:
The most expensive carb one will ever buy.....
is the wrong carb one tries to modify!
Jon.
