When I put in the new
engine I kept the original prop as I figured the
engine was sort of similar to what I had.
What I'm thinking is why not try with the prop you have now. Take the
boat out and (keeping running in recommendations in mind), do some measured runs at various rpm's checking with the
GPS. Make careful notes allowing for tide,
wind and
current. Even see how you go against some serious chop and swell.
From that you should be able to go back to the prop people (or this Forum!!!) and get some informed opinions on what is best.
If
money were no object I'd suggest a feathering prop (see Forum for opinions).
I found that my original prop had way too much pitch. Even with the prop shop taking off more than I requested I still have a bit too much (2300
rpm as opposed to a desired 2500). But I think that I can live with what I have. The boats not perfect anyway...
Don't forget that as fouling builds up it will chew up some of your speed and
power. My experience suggests that a slightly smaller, under pitched prop may give a better long term result, as long as you take care not to over rev the engine.
Your engine has lots of
power so the old
rule of running at 80% power may not be applicable. My experience suggests a possibility of using 20 - 40% power for long periods.