Here an example of why looking at any one aspect of a set of heads doesn’t even begin to tell you how they’ll work.

I freshened a set of Indy 572-13’s last year. They came off a motor built by a very well known big name Mopar builder.
Cnc ported, 2.350 intake valve....... they’re used on a high CR 588 making over 1000hp.
Flow@.400?? 250.