Is the HP figure inflated.......don't really know..........would they lie........maybe, don't rightly know. It comes down to damage of their ethics and credibility if they got caught, don't know why they would risk the possibility, it is their bread and butter.
Dulitch went on to write 3 or 4 more articles about 400 plus HP 318's, different recipes, none of which were all that special; of the ones built, I would say this one is the most difficult to reproduce due to port work done to the heads.
It is a good build, cuz it does say "look what can be done" with what is other wise a throw away. Your results may vary.