1974 jet w/455 olds

[Miller83]

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?

[Lt. Holden]

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.

[johnmillerboats]

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.

[FAST FRED]

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.

FF

[drmiller100]

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.