RE: [omc-boats] New Engine

From: Lee Shuster \(L1hhs\) <lib1@...>
Date: Fri, 24 Mar 2006 09:26:12 -0700

Hi Bill,

I faced the same issue last winter with my 1966 Evinrude Sportsman V6. I
ended up going with a 307 Chevy V8, but you could use any pre '86 small
block Chevy from 265 to 400 cu in. (OMC also used a lot of 302 and 351
Ford V8's in the mid-seventies, but they all have short-shaft lower

For a number of reasons, you'll want to seriously consider changing the
OMC lower unit to get the benefit of the .86/1.16 gearing. Running your
V6 gearing behind the V8 is not recommended.

You can view pictures of my conversion project at:

Since your boat is a later model than mine, you will already have the
front and rear floor motor mount pads. The V8 is about 4-inches longer,
a tad narrower, and about the same height as the Buick V6. You'll pick
up about 90 pounds of weight, not really an issue. The smoothness,
especially at idle is remarkable. The fuel economy is certainly no
worse, unless you continuously run it flat out. In fact, the V8 may
return better economy if you do a lot of 25 mph cruising, simply due to
the lower rpm and the fact that the QuadraJet is a great carb,
especially running on it's spreadbore primaries. You don't pick up as
much flatout speed and performance as you might think. Maybe 2 to 4 mph.

In my opinion you do this upgrade to gain the benefit of having an easy
to service, reliable, small block Chevy (oh yeah, it's dead quiet at
idle too, but when you open those Q-Jet secondaries, she sounds very

Lee Shuster
Salt Lake City

-----Original Message-----
From: owner-omc-boats@... [mailto:owner-omc-boats@...]
On Behalf Of Bill Whitlock
Sent: Friday, February 24, 2006 7:25 AM
To: omc-boats@...
Subject: [omc-boats] New Engine

I have a 1968 Johnson Seasport II that I am working on to get back in
the water this spring. I have about figured out that it will cost more
to try and fix the current (original) Buick engine than it will cost to
replace it. Has anyone dropped another engine in this boat other than
the Buick?

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Received on Friday, 24 February 2006

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