Re: outboard to transom
We'll assume we're talking about mid size to higher hp motors.
On my boat I like to have some aluminum to protect the fiberglass. Something like a Bobs Machine hydraulic jackplate.
Seriously, a lot of people (including myself) like to have a thin piece of aluminum to protect the glass. We like to make a "diaper" that goes over the transon and protects the inside (top bolt holes) and down the outside (all 4 holes. Then use a plate inside on the bottom 2 bolts.