Re: 3 blade, 4 blade?
A 3 blade gives good overall performance with good top end.
Generally a 4 blade will improve low and mid range performance.ie: better hole shot,stay on plane with less throttle,smoother,better control on plane and at the dock. usually 2 to 3 mph top end loss.though there are exceptions where speed is maintained or increased.If you tell us the details of your present performance and what yopu hope to have, we may be able to help.