There’s a couple pieces of info that I’d add as “ must knows”: the intake valve size, and the lift where that max flow is measured.
I also use “2hp/cfm”, but I add the caveat of “within the lift range of your cam choice.” Try as you might, a max effort 300cfm @ .700 lift port that flows 230cfm @ .400 is not going to make 600 hp. Yeah I need the rest of the info.
Chamber shape is important, but I’d also suggest in the example engine you provide, chamber is only a means to a compression ratio target. Nothing more. A higher hp/inch effort certainly. Restricted fuel rules certainly. But a pump gas 408 making 500hp, it’s just not.
