Need a little info about props

[BASSKING]

Guys, I have a 15hp force/gamefisher tiller engeine and would like to put a three blade prop on it but i am a little confused. the prop on it now is a two blade 8 1/4 diamater x 8 1/4 pitch. would the diamater and pitch be the same for a three blade prop? any help is much appreiciated, Thanks

[CTFSHWHISKER]

pitch should stay the same the diameter may be a little bit smaller to make up for the extra pull of the third blade,if they are the same as bass boat props.8 1\4" pitch is the same regardless of how many blades i doubt you'll lose anything rpm wise even it the diameter is the same.the extra blade will also add some tourque so it should perform better period at the same size.