Inliners International Forums General Discussion Engines 216 Build: Some Under Hood Details

Those are Carter WCD - model 5340 - which was OEM on the '53 Nash Statesman with a 195ci flat-head six rated at 100hp. Carter never published CFM data for these. I have never seen anything (estimates) online either.

These are a three bolt base with a dual 1 inch flange (like the Stromberg 97). There are three venturi:
Primary 11/32"
Secondary 21/32"
Main 1-1/16"