TOPIC: Going to bring her back to life

My old boat that I used as a tender is going to be brought back as I finally found a new engine for it. Hurricane Irma took it so it isnt much ore than a hull with potential right now. Ive been looking for a good deal on an engine and just got one 2 days ago, I wanted an I6 Merc. I traded for the motor not knowing much about it so Ive been trying to figure out year/hp. The cowlings are there but its degraded to simply aluminum with no markings. Serial number on the bracket is 4749859, there is no low water pickup and measures 20 inches roughly from bracket to cav plate.

I found some more numbers on the block which makes me more confused.

Hmm, I tried looking on Marineengine.com but they don't start until '82 for serial number search. I'm sure the good Dr. Frankenmerc knows how to tell.

Bob