[samuelcooper]

For what it is worth, I have a good friend who has a 1966 20 ft Bertram which he has had since it was new. For the past 15 or so years, he's been running the 4.3 v6 with mercruiser sterndrive. She runs very sweet, quiet, and uses WAY less fuel than I did with a 130 Johnson pushing an 18 ft, much lighter boat. From what I have heard, the omc sterndrives are close to junk. I don't know what the conversion would cost or even it it is possible. Also, I think if you run in saltwater, a heat exchanger is a necessity.