Ha ha.......no hits out on Doug......yes, I took the previous version, ground a little, filled a little, had a new cutter made with slight changes. It is really surprising how little difference there is, yet changed in the right places.....makes a significant difference. The prototype port then gets digitized, and programs are created from that map. A porter can spend all the time tweaking one port....then make it repeatable. The CNC machines made high-end head work affordable versus hand labor. There is so much material to remove in a Pro Port casting, it would be a huge job to port 16 holes by hand. Light touch-up and mild porting is still feasible in some heads and in some cases, but for big stock removal, the CNC is the only practical answer.