I have a 150 Mercury XR6 on a 25ft Pontoon so it pushes a lot of weight and has a lot of drag. Right now I run an 15 1/4 by 15 quicksilver prop. Now I bought this boat with this prop and have lived with it. It runs wide open at 5300 rpm's and I would like to switch props to get Mercury engine specs which are 5600 at full throttle. I know that isn't much difference but I feel like the boat over all should run a little higher RPM if needed. Any suggestion would be appreciated. I was thinking maybe go to a 14.5 diameter with a 17 pitch. But I'm not sure... I would like to stick with aluminum. What do you think a good prop size would be?