Older 305 to Newer 350 swap, Mercruiser Alpha Gen I

Discussion in 'Sterndrives' started by duke, Jan 5, 2011.

  1. duke
    Joined: Jun 2009
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    Location: Seattle

    duke Junior Member

    I've got a merc 898 (305 Chev, 1978) with a newer reman'd leg (Alpha gen-1 style, new in '07, running 1.47:1). I'm swapping the old engine with a brand new, zero hour, 350 TBI from Kodiak Marine. The new engine comes with a 14" flywheel, and I've ordered a conversion 12.75" flywheel. The bolt pattern is different, of course, so my drive coupler will need to be replaced also. Does anyone know the part number or description I'll be looking for?

    Thanks,

    -duke
     
  2. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    Why are you changing the flywheel? If you do, the starter won't work. You will run into balancing problems with an old style flywheel too.
     
  3. duke
    Joined: Jun 2009
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    duke Junior Member

    I have to couple the new engine to the old bell housing, so I was planning using my old starter (from the 305 with the 12.75 ring gear). my old bell-housing is my only option, (as my motor mounts won't change and the shift linkage will bolt back on). I was under the impression I needed to drop down the flywheel size to keep my old bell-housing. Either way I need a coupler that works on the new crank/flywheel bolt pattern.

    Am I missing something else? You seem to be one of the more knowledgeable people on this forum, so let me know what you're thinking.

    -duke
     
  4. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    The starter is bolted to the block. Bellhousings are really cheap compared to the cost of a custom conversion like you are talking about. Also, custom balancing an engine to fit a different flywheel is quite hard.
     
  5. duke
    Joined: Jun 2009
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    duke Junior Member

    Well, the flywheel is a custom job from the engine manufacturer. And, I know where a starter bolts on. But let's follow your path for a moment--Ok, what bellhousing would I need to keep my old gimbal and leg while using the new flywheel, and starter? And, once again, what engine coupler?

    I'm really looking for some solid application of part numbers, descriptions, etc. I have a brand new engine, it cannot couple to my old gimbal and leg without some additional parts. Can someone spell out what parts they think those are, rather than just tell me what I don't have or can't do? That's all I'm looking for here.
     

  6. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

    Look at ebasicpower.com
     
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