OMC to Merc Conversion

Robert4Winns

Petty Officer 2nd Class
Joined
Oct 28, 2009
Messages
146
I have a 1989 Four Winns Freedom in which I am currently replacing all of the rotten wood. It has a 3.0L OMC Cobra. The engine and drive work fine and there is no reason to replace them other than they are OMC.

But as it turns out I can get a donor boat with a Mercruiser drive and straight 6 engine. I don?t have a lot of details on the engine and drive, but I am reasonably sure I can get it running, and would do so before pulling it from the donor boat. I don?t know the exact year of the engine and drive but believe they are mid 70?s.

My question is would the fact that I would have a straight 6 Merc, as opposed to a 4 cylinder OMC make it a worthwhile swap even though it is a much older engine and drive?

I am not concerned about the difference in the front motor mount since mine was rotten already and I have to build a new one. I just replaced the transom and cut the drive hole to fit the OMC and I don?t want to have to redo that part. But I saw somewhere here that the drive hole is the same. Is that true?

Here is a photo of the drive I would be installing. Any thoughts or comments would be appreciated.
 

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Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: OMC to Merc Conversion

The cutout for the Cobra and your Merc are identical. Go for it.
 

Robert4Winns

Petty Officer 2nd Class
Joined
Oct 28, 2009
Messages
146
Re: OMC to Merc Conversion

Thanks Don.

Can I use the same controls and steering or do I have to take those from the donor boat as well?
 
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