[ThePHNX]

Blue Heron;
Ours is an SF20 but till we've repropped we're out of the water, anyway, at this point it would be the blind leading the blind - in fact you sound like you know a hell of a lot more than we.
Don't know how much land based performance tweaking translates to the water, but when we were trying to get the last inch of speed and power out of a custom engine - or even relatively stock - we'd standardize fuel and stick with it, set the cams with a degree wheel, choose plug heat range CAREFULLY, and advance spark till she pinged and then back it off a hair. Such empirical methods have the advantage of dealing with the engine's `personality' there are no two exactly alike. HBH