I put together this spreadsheet for everyone's reference comparing square surface area across throttle body bores, cfm airflow capability, and what type of horsepower your particular throttle body should support. These numbers could be used for maf sizing and cfm (not hp for maf as that has alot to do with voltage of the meter as well). Hope all enjoy. Mathematical calculations were made and then I used a base throttle body that had been measured for actual flow and applied to other sizes to get approximate cfm and hp calculations. Chart is sized from smallest square surface area to largest.