[Barry_R]

Back before the marketing BS took over, four barrel carbs carbs were SAE WOT airflow rated at 1.5" of vacuum drop below the throttle while flowing a standard fluid with characteristics that were supposed to be comparable to gasoline. You NEED a standardized vacuum level to establish any comparable flow rating. The 1.5" was used in 1957 because it was 1/2 of the 3" standard previously used for two barrel carbs - - the test equipment already in place would not pull 3" with a four barrel. The value derived is simply a measurement, and is frequently and improperly used to determine the best carb size for an engine.

EFI throttle bodies are rated - it seems - by taking a wild assed guess and multiplying it by at least 150%. Same holds true for many "race modified carbs". There is simply no way that a carb shiner upper can get 1000 wet cfm @ 1.5" out of an 850 base plate on a 750 carb body - - so the wild numbers are guaranteed to be "dry" ratings.

I would guage airflow potential by just comparing throttle plate diameters (and booster/venturi dimensions on carbs). Just remember that carbs are wet flow, and will thus deliver a lower real value than EFI throttle bodies - fuel takes up room. Perhaps 20% of the flow rating....

As to power for EFI versus carb - - we've tried that - - published in Hot Rod in August 2004. Took an EFI converted Dove intake on a 505 inch FE and ran it with a comparable bore HP carb. The difference was in the carb's favor by single digits for power and TQ throughout the curve. The EFI was much better driving in the car though - particularly at idle and part throttle/transition.