I have tested this many times, and unless lots of work is done to the entry of the carb, BESIDES the choke milled off, NOTHING will happen, It does NOT pickup anything on the flow bench or on the dyno. Now let me say this, IF the carb has been rerworked by someone who knows what they are doing, it CAN gain up to 30 0r 40 CFM, BUT not by just cutting off the choke.The smaller the carb) (650-750 ) the LESS you might gain. I have reworked carbs and used the flow bench to verify the results. The biggest gains come from making all four barrels flow the same. From Holley, they very quite a bit( 5 to 10 ) CFM.

JOE SHERMAN RACING ENGINES