Here are numbers I have seen and a few estimated for the 2100s. These are all at 3" Hg. To compare them to the (usual) rating of 4v carbs at 1.5" Hg, take the numbers below and divide by 1.414.
My approximate guesses are in (Parenthesis)
Any additional factory CFM ratings appreciated!
So, a pair of those 1.14 2100 carbs would flow about the same as a single "Mustang" 1.08 x 1.19 4100 small 4v carb, and the ratings at 1.5" jive with that since 223+223~440cfm, the rating of the "1.08" 4v 4100.