Prop Selection??

[Balsl6]

I have a 1994 Crestliner 170 Sport fish w/ a Johnson 115 H.P.
I bought it late last fall and the dealer put a 13 1/2 x 17 it runs high rpm's (6300) I think? It goes about 35 mph (boat spedometer). I was told to run a 14 x 17 prop will the 1/2" make that much of a difference?
Does any body have a comparable boat ? How fast and what rpm?

Thanks

[Starfish]

I would think a 19" pitch prop, preferably cupped, would make more sense than a larger diameter prop of the same pitch.

[Balsl6]

I was told buy a differnt dealer that the 14"x17" was cupped??
Does that make sense?

Thanks for the help.