RE: Old 3.5 K&B outboard setup help
You can also try adding trim plates to the rear of the sponsons. They can easily be bent up in a vise out of some sheet metal or brass stock and used with the added nose weight that Ron mentioned. If you can keep the attitude of the hull straight by itself and not rely too much on motor tilt which will remove speed from the prop, you should be left with some pretty good top end with it.