Flow numbers and max HP potential

The motor in the car that ran 8.33@165 made 918hp on the engine dyno....... with heads that flowed 390.

918/390 = 2.353hp/ci

This motor would have picked up 30-50hp just by installing a tunnel ram intake and 2 x 1050 carbs.
It could have been built with a little more compression, which would have facilitated a little more duration.
The valve lift was kept in check so the springs would have a reasonable life.
The vacuum pump used sucked, and would only pull about 4”.
If the motor would have been run with 10-12”, more power would have been made.
The motor had a very generic, fairly shallow dragster type of oil pan.
Something deeper, along with a crank scraper would have freed up a few ponies.
Those are all things that would show as additional HP...... that wouldn’t require the heads to flow any more on the flow bench.
Being fairly conservative, I’d say there was an easy 60-70hp left in that combo without reworking the heads any more.
That would put the hp/cfm level up around 2.5hp/cfm.

Brett Miller built a Victor headed 440” SBM a couple years ago.
Made over 1000hp with heads that flowed under 400cfm.