I have a 3 blade prop that is slipping. Wondering about going with a 4 blade prop. My current prop is 10" with a 13" pitch 3 blade. It is running at 5500 rpm wot. Which is right within where it should be. Wondering what would be the correct pitch in a 4 blade. Also what would I lose in speed. I hit a top speed of 16 mph right now. I don't want to lose much speed 