Can I replace a '79 straight 6 with an '82 470 ?

[jimmoe]

Hey Guys.....
I bought a 79 Searay that I like with a frozen 6 cyl 165hp mercruiser that had water in the oil and I could not break loose. I'm have trouble finding a used replacement for it (I am on a tight budget). There are several 470's available locally, I even have one that has a cracked block, an '82 with a good gimbal assembly and outdrive and all other components (including a good 4" heat exchanger).
Wondering if anyone can tell me what kinda challenge this would be ?
Would the gimbal housings and assembly match ?
Could I install an entire 470 with it's Gimball housing and outdrive without having to modify the cutout in the transom?
I'd appreciate any advice before starting this project. Thanks !

 

[Bondo]

Ayuh,..... You Don't want a 470, no how, no way,.....

There are millions of Chevy 250 I-6s out there, 'n parts can still be bought,.....

Not so, for the 470s,.....

 

[Rick Stephens]

6 Cylinder I6 Chev is the way to go. Find one in a wrecking yard and build her up.

 

[Mercruiser420]

470$ can be headache$... Given nothing has been modified, Any straight 82 (120, 140, 165, 470) engine will fit right where any straight 79 engine was. Same gimbal housing, transom plate, exhaust pipe..83 is different. Do your research though, use part numbers to be certain. If you can get a complete 470, 1976-1982 with the right exhaust manifold (cast iron) and riser(elbow) that dont leak, it'll be cheesecake. Try to find one with an alternator. Much more reliable than the stock charging system. Good luck

 

[Howard Sterndrive]

another vote for sticking with the 165 inline 6.

 

[bruceb58]

You would never want to put a 470 in a boat on purpose!

 

[Scott06]

250 straight 6 bullet proof,

470 not so much

 

[thumpar]

You would be going backward going to a 470.

 

[jimmoe]

Thanks for all the advice, seems to be all saying the same thing.....I'll keep looking for an
I-6.
"470$ can be headache$... Given nothing has been modified, Any straight 82 (120, 140, 165, 470) engine will fit right where any straight 79 engine was. Same gimbal housing, transom plate, exhaust pipe..83 is different." This is great information, thanks, Merc !