Trick flow

I think it's easier to understand the relationship between flow and volume is to look at a pcar head and a W-2 head.

You can work your guts out on a pcar head and get 260-265 CFM. A W-2 with a decent valve job will wake that CFM but be 70-80 HP better. It's a volume issue.

All these big inch small blocks are severely under headed as far as volume goes.