Re: 40hp outboard prop??
You can raise the motor some by just putting a stick on top of the transom to hold the height till you tighten the clamps.Add a 1/4 to 1/2" at a time just be sure the clamps have a good grip.
I assume your steering is forward move some weight to the stern try full trim may not do anything but give it a try.You might see if they can do anything with your present prop.
On a light fast boat speeds are possible up to about 32-35.If the boat has full rear deck,split cebter deck,front deck and wind shield it is about 350 lbs dry.bare boat with short front deck is about 240.If it has forward steering you could gain a couple of mph by unhooking and steering at the stern with the tiller.Not practical but faster.