Tinker,
I lost 5 mph between the two props:mad:

That is because you went under your torque curve. I was still in my torque curve or was creating enough to overcome the extra load. (Twin engines)

Your TQ curve is increadibly flat. I've allways maintained that a smaller pitch prop spun faster is more efficient that a larger pitch spinning slower. Is your case just proving this?

CobraMarty,
Yes I seem to be proving this on this boat.
Even when I had the stock 502mpi (64gps) I stepped down from a 23 Mirage to a 22 Hydro and the boat picked up almost 2mph.