Horsepower, compression ratio, airflow?

I think it's all really just tossing out ideas, simply because even if we all had a flowbench and dyno, every single engien package would be unique. Too many variables.

I think it's a lot like the "2hp per cfm" guideline. There's a lot of people that can exceed that. But, "in general" you can expect that.

As far as my own determinations... I start with fuel type, intended hp level, and displacement and go from there. Now hypothetically, given the choice between as much compression as I want, or as much head flow as I want, I'd go with head flow.