I just got a new used motor and it came with a 10 3/8" by 11p prop. When running wide open it goes 30mph at 5750 rpms and it feels like I have a lot more throttle left. I also had some slippage if I gave it too much gas during take off. If I go with the mercury website recommendation I should have a 10.5" by 14p prop. How will this change things for me? I believe it will give me a more speed and lesss rpm's am I correct?