I don't know if anyone can answer that question but from my years of working at Hallett boats I never saw anyone really happier with 1.32:1 gears after we made the switch. Some boaters didn't like it. We could never figure out which boats needed it (the exception was really high horsepower boats but they would blow Bravo drives every weekend so who knew?)I am not much help here but if the boat will handle a higher pitch prop without being tossed around by the aggresive pitch I would think that the 1.50:1 would be my choice.
Dennis Moore
Merc Master Tech