[PC/SR]

Railcar's "flow meter" is great for getting carb balance, but there is more to tuning than getting the air flow equal. Usually using bigger dual throat carbs are going to result in a bit gulp of air and a lean mixture when you stomp on it with some coughing and spitting, and it takes trial and error to eliminate that. (See Dodge, #38) Nothing wrong with the carbs, they are just not right for the application.
The three main variables are idle adjustment, main jet size and float level, and throw in the accelerator pump adjustment just to add to the problem because the kits usually have a different length pump shaft than stock on the Holleys (not a problem on the Stoms.) Add in the Holley power valve on dual carb applications (you must use aftermarket valves for dual use) and it gets sort of tricky. Work on the power valve nozzles.
For ordinary street driving, use the Stromberg 81s or the Holley Model 92s(.875 venture) and things are pretty easy and good. If you want more, the Holley 94 and Strom 97 are fine but a bit more tricky to get right and not much different in performance from the 81's for most street applications.
For more HP, use the bigger Holley EB and EC series from the '54-56 OHV, or the big Strom 48 but as Railcar says, too big for street driving.