[CaptGorges]

Not sure that this answers any of your questions, but it has seemed to me through owning several cars that I have put "power-chips" or whatever, I have never been able to gain more than 10-15 hp, but I guess Ive never tried to retard the timing to reduce HP. And most cars are already tuned for optimum performance, you cant get a whole lot more out of them. Maybe in the example you used on Verados, assuming it is the same block and supercharger and all, you may be correct. Ive always wondered though about chipping a marine diesel motor. My dad has a '05 GMC Duramax and he has a programable chip that you can tune to +50, +100, or +150 with the push of a button. And she will SCREAM. Other guys I know with diesel trucks have chips that allow you to do more to the system (fuel/o2 ratio and whatnot), dad's just does HP. Im going to put a KAD43 Volvo in a boat soon, an early 2000's model (235HP/500Ft-lbs, cruises the boat at 28mph @ 3200RPM @ 3.5GPH, WOT is 35@3900@>5GPH) with a computer, and Ive wondered if on longer trips (stream and such) if I could crank it up another 100HP for the run out, burn a little more fuel, and run a little closer to 35-40MPH at cruise, and then tune it back down to still troll at 1GPH.