1974 jet w/455 olds

Discussion in 'Powerboats' started by Miller83, Feb 25, 2009.

  1. Miller83
    Joined: Feb 2009
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    Location: Palm Springs,CA

    Miller83 New Member

    I was wondering last summer i Blew my 1974 455 oldsmobile motor and i was wondering if i should spend time and money to repair it or if i should go with a chevy motor?
  2. Lt. Holden
    Joined: Sep 2007
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    Location: Western Massachusetts

    Lt. Holden Senior Member

    If you can get some $ for the manifolds etc. I would strongly recommend the Big Rat motor, widely available (and cheaper) engines and conversion parts, more H.P. and better reliability. FWIW, years ago a friend replaced a blown 455 c.i. in his Sidewinder 18' with a 402 c.i. (396 O/B) and said it was like driving a brand new boat.
  3. johnmillerboats
    Joined: Sep 2007
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    Location: Arroyo Grande, CA

    johnmillerboats Junior Member

    Miller83: Is your boat a Miller? If so, my family built it.
    If you plan on keeping the boat, it would be better but more expensive to replace the motor with a BBC. Try to find some used mounts and ex. manifolds first cause new ones could run about $1000.00.
    Go with a 454! Jets need big cubic inch motors. You probably should overhaul the pump too, If your boat is a 74' Miller, you have a Jacuzzi. I would look into some after market stuff that converts the pump to a Berkeley style pump which works better.
    Joined: Oct 2002
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    Location: Conn in summers , Ortona FL in winter , with big d

    FAST FRED Senior Member

    When GM was building motor homes they needed a really HEAVY DUTY engine .

    With the entire inventory of GM engines they chose the OLDS as the best at Very hard work.

    That's why so many are in boats , they can take it with little modification.

    Other motors are cheaper , so what?, there NOT BETTER, just cheaper.


  5. drmiller100
    Joined: Feb 2009
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    Location: Idaho

    drmiller100 Junior Member

    when gm engine looked around and realized it had like 9 different big blocks, it settled on one to continue building.
    40 years later it is discontinuing the 454, but the rest have been gone for the past 30 years.
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