Speedmaster head hypothetical
The 50. Look at your low lift numbers. Are you using a cutter or stones to do the seats?
Edit: I forgot to mention your high lift numbers. Or mid to high lift anyway.
I care far far more about the shape of the curve over .25 l/d than I do low lift flow numbers.
For me, testing low lift (lets say .100-.350 lift) testing should be done at the highest test pressure the bench will pull.
If I’m testing just lifts above that I usually test at 10 inches or so. Plus all the other ways I’ve mentioned.
It makes a ton of paper and data but you start to see why CFM isn’t the best indicator of what a head will make for power.