Not sure what to make of this thread. Is the art of porting mainly based on some individual personal theories, with a prodigious amount of try and error on a flow bench? What happens when flow changes go down instead of up? If the art is slowly dying off, because of time and CNC, seems like the time for a well researched jointly written book, with chapters by each of the prominent willing head porters. Seems like the book would be able to be well priced if the secrets are shared by those in the twilight of their profession. The attraction to me would be reading all the different views, one, not so much.