MC165 Engine bed height

[Sangster21]

Uh oh, I can't seem to find some of the notes I made when tearing my boat down. How do I go about figuring out the engine bed (mount) height. I specifically measured down from the gunnels to get the vertical position of the front engine mount for my Mercruiser 165 I6 engine, unfortunately not so useful if I don't have my notes anymore.:facepalm: How do I reference from the existing keyhole to figure out where the engine mount sits? Just got my transom and stringers tabbed in and will need to start of engine mounting soon. Thank you.
Alan