So we go through this again: Twice in the same thread!

Two barrel carbs are rated at a 3 inch pressure drop across the carb. Four barrel carbs are rated at 1.5 inches of pressure drop. To convert from a two barrel rating to a four barrel rating you DIVIDE BY THE SQUARE ROOT OF TWO!!!
That's 1.414... for those who don't have a calculator with a square root key.

1350 / SQRT2 = 955cfm.

1150 / SQRT2 = 813cfm.

etc.

R.