how many cfm for two carb flathead??

[derek costello]

If we are to believe that a late model ford flathead is only supposed to require
about 300 CFM of carbaration and that is further reduced by an efficiency ratio of 82 percent, then we are to work with 247 cubic feet per minute for the design
of carburetors !
A typical Stronberg 97 is rated at 150cfm's and holly 94s are rated at 162cfm's?
So any combination of duel carbs is going to be way over the requirement of any but the wildest modified flathead.......? What gives???