I have a 87 merucury 50hp 2 stroke on a 16ft starcraft sfm160 v-hull. It comes out of the hole great and planes out good. It currnetly has I think a 12 pitch prop. What I was wanting to know is should I change the prop or add a jack plate to the boat. Right now it goes 31 on gps for my top speed. I would like to know if anyoine could tell me how much more I would get out of the jackplate and how much from the prop. I dont have enough money to buy both. My goal is to reach at least 38-40 with this 50hp. Is it impossible?? Please help me thanks Jayme