That head actually flows OK after it was cleaned up in the valve area & chamber work were done.

From your pics, the long turn can use a lot more opening up, IF, the casting allows you to do so?

Another way of seeing how the air flow is by using a stick & attach a piece of tape to it & insert the stick w/tape into the port & see where the tape goes.

Good luck with the porting, it is a time consuming art & takes a lot of patience.

Don't worry about polishing , that is just cosmetics for the most part. Makes the customer say WOW! \:D

What tool are you using for porting & what bits/tips?

12 port SDS EFI