Prop pitch?
 

I have a Bayliner 2352 walk-around. The original 305/210hp motor failed. I replaced it with a 350 with 350-375hp(guessing on the hp but comparing with a very similar build engine dyno sheet)

The original prop was a ss 15 pitch prop.
Any guesses or formulas to figure out what pitch prop I should start with for the new engine?

The Mercury prop selector is a neat tool to play with, might give you some insight.
https://www.mercurymarine.com/en/us/...or/#!/step-one

On that hull, you might step up to a 17P. I'd try the original first to see where you end up.

I use this on a 2452 with a 325 hp motor. If you can find someone to add 1 inch pitch it will be perfect.
https://www.partsvu.com/blkdia-16r16...gaAjjFEALw_wcB