David Vizard bench flows a BBD 2bbl

If the engine built to displace about 500cfm is gonna basically do it no matter what carb you run, carbs only flow a specific cfm on a flow bench, on different engines they flow different amounts at wide open. It's just the two barrel and intake is way more restrictive which will kill say 50 hp which will bring down the cfm the engine will displace somewhat but still be way over the carbs 250 cfm. And the holley 500 cfm two barrel is rated like a two barrel so really be closer to the 318 one.