[muddywater]

I remember that Will had measured my transom notch when I bought mine because my boat's transom notch (1972) was skinnier than his (which I think is a 78 right?). I think he decided his was set up for twin 70's or something.

Anyway, my original 20" height transom is about 33" wide at the top and about 22" at the bottom. Keep in mind those measurements could be an inch off since I have a motor in the way. If you raise it 5" the bottom width would of course be a little wider since the sides are at an angle. Although the motor has plenty of room, I am not sure about the Seastar system since I don't have one (yet)