Looking at the previous pictures, the motor is currently mounted fairly low so you should be able to raise her a couple holes creating better performance along with turning a bigger prop, say a 3x16x18.5. I know top speed is not a priority, but, by dialing in the motor height and then swinging the absolute best performing prop, I think that should get you 42-43 knots top end to go along with a faster cruise at 3500 to 4000 rpms running say 26-28 knots. Also, your boat does not have bottom paint?