I always flow a head befor and after porting a head and if it is a head I never played with befor I probably have it on the bench 6-10 times. Its only another tool but if you have the time its time well spent. Instead of posting posting flow numbers I would rather see how many cfm you picked up on any given head on your bench. example(head flowed 267cfm@28 befor and 298cfm@28 after.