I don’t know this guy but he has a pretty informative video about head flow. It’s chebby stuff but I’m sure the principals apply to most brand cylinder heads. It’s a 16 min vid but helps shine light on why cnc porting these heads may not improve flow without some other changes.
https://m.youtube.com/watch?v=eJi7drOyTmQ
I like his comment on how flow is impacted an inch before and and inch after intake valve.