I was told to go from my 13 1/4 x 17 to 13 1/2 x 15 from the prop shop. So I hope they lead me the right way
I tried a new prop last season too based on the advice from the prop shop. Unfortunately, their advice was inaccurate. It resulted in a very slow hole shot and a reduced top end speed, so I brought it back and went right back to my previous 4-blade prop.
About the only way to get a good answer is through trial and error. Good luck