I have a 1998 Johnson 9.9hp 4 stroke with a 9x11 3 blade prop. This is what came with the motor when I bought it used about 6 months ago. Now according to the Manufacturers Specs, it should have a 10x9 4 blade prop. So my question is this, which prop will give me more gogo, the 10x9 or the 9x11? Any ideas?