Re: Jack plate question
Why don't you post some photos of your engine when it's down, try to get the hull level and the engine level. Then some of the people here with experience setting up jack plates can comment.
You're not going to want to set jack plate height based on trailering the boat, all you should concern yourself with is what the boat does in the water. You'll just have to find a way to deal with trailering issues. As suggested, raise it up 'till you know it's too high then lower it 'till you're happy. HOWEVER, I wouldn't suggest doing this without a water pressure gauge - at some point your lower unit can be so high that the water inlets will be largely uncovered and you could fry your engine. If you get to the point where your water pressure starts to drop back off the throttle immediately, idle back to the dock, and drop the jack plate down to where the water pressure was good - unless you modify the water inlets you won't be able to go any higher.
Just as a reference (your hull will undoubtedly be different) I also have a 6" jackplate and have it adjusted to where the prop centerline is 2-1/2 inches below the pad.
