RE: Engine height K & B 3.5
I had one of those about 10 years ago! A good starting spot is with the prop shaft about 1/16" above the bottom of the sponsons and the engine level with the transom then adjust in small increments from there.
What I didn't like was the radio box setup, it was hard to tape down the cover.
The other K&B would be fine for a Top Speed 2.