Thanks - interesting analysis!

My hull speed is actually around 7.5 knots, but 6.5 at 2500 IS my target cruise.
I suspect slippage is higher at these speeds, so I'm still leaning towards 10in
pitch. Working backwards: a shaft RPM of about 1220 and a speed of 7,900
inches per minute at 10-in pitch gives a slip of 35% - within reason as we
approach hull speed.
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Lloyd, the risk of going to too high a pitch is lugging the engine.
If you try the 14 x 10 prop and you can't get to 3,000 RPM at wide
open throttle or get black smoke in the exhaust at WOT, the engine is
lugging. If so, I'd strongly recommend getting the it re-pitched back
to 14 x 9, or have an agreement in place for exchanging the prop. You
don't want to risk damaging that brand new engine! 3-bladed props
have significantly less slip than 2-bladed.