305ci Engine Replacement - Auto Block?

ajax5240

Petty Officer 2nd Class
Joined
Aug 6, 2011
Messages
134
Hi all, I spent some time searching to see if this question has been asked before. But no luck. I apologize if I am asking a question that has been answered 50 times already.

I am looking at a 1985 Bayliner Capri with a 305c.i. engine and a OMC Drive. The block is cracked due to the previous owner not knowing how to properly winterize a boat.

My question is, can I go to a junk yard and get a 305 Chevy engine out of a pick up truck, swap the marine parts over to the new block (after plenty of inspection of the new block and rotating assembly of course) and stuff her back in the boat? Or are there differences that would prevent that?

2nd follow up question, what would it take to stick a 350 in there instead as there are not many differences between the 305 and the 350 in the car world.

Thank you very much for any help and advise! I always get great answers from you gentlemen on here.

Cheers!
 

RogersJetboat454

Commander
Joined
Jul 9, 2010
Messages
2,964
Re: 305ci Engine Replacement - Auto Block?

Actually the question has probably been asked thousands of times... but who's counting ;)

Yes, you can use a 305 or 350 from a boneyard. You need to swap all marine fuel, and electrical parts over. Chances are if the block is cracked, the exhaust and intake may be cracked as well, so budget accordingly. The core plugs (mistakenly called "freeze plugs" by most) should be changed to brass, and the head gaskets to marine grade if you intend on using this in salt water.

Since it's an '85 engine were talking about, look for an '85 or older donor engine. '86 was the first year for Chevy to have a 1 piece rear main seal, and the flywheel is different, meaning your coupler may not jive with the different style flywheel.

While we're on the topic of questions that are frequently asked, I'll take the liberty of asking one for you;
Q, Is an 1985 OMC "Stringer" a good drive.
A, While they were an OK drive back in the day, 1985 was the last year for them, and OMC has been out of business for the last 13 years. Parts availability is spotty, and getting worse as the years go by. Most members on this forum, even the ones who own such a drive say if they were buying another boat, they'd stay clear of them.
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,130
Re: 305ci Engine Replacement - Auto Block?

Hi all, I spent some time searching to see if this question has been asked before. But no luck. I apologize if I am asking a question that has been answered 50 times already.

I am looking at a 1985 Bayliner Capri with a 305c.i. engine and a OMC Drive. The block is cracked due to the previous owner not knowing how to properly winterize a boat.

My question is, can I go to a junk yard and get a 305 Chevy engine out of a pick up truck, swap the marine parts over to the new block (after plenty of inspection of the new block and rotating assembly of course) and stuff her back in the boat? Or are there differences that would prevent that?

2nd follow up question, what would it take to stick a 350 in there instead as there are not many differences between the 305 and the 350 in the car world.

Thank you very much for any help and advise! I always get great answers from you gentlemen on here.

Cheers!

Ayuh,.... Keep Lookin',... Run away from that boat,... Free is 100 times more than it's worth to you....

Listen to what RogersJetboat454 is sayin'.....
 

ajax5240

Petty Officer 2nd Class
Joined
Aug 6, 2011
Messages
134
Re: 305ci Engine Replacement - Auto Block?

I appreciate the advise fellas! It was listed pretty cheap ($1250 with new interior) and was thinking that I have some stuff to barter for it. That is very good to know about the OMC Drives, I'm not looking for any more of a headache than owning a boat has to be. Just got done with a floor in a '84 16' Capri and would love to have the extra 3 feet that this one offers (19'er). Not to mention the V8 upgrade from the AQ125 4cyl thats in my current capri.

I'm in Colorado, so no worry about salt water..

Thanks again for taking the time to reply and pass along your knowledge and experience!!
 

RogersJetboat454

Commander
Joined
Jul 9, 2010
Messages
2,964
Re: 305ci Engine Replacement - Auto Block?

I appreciate the advise fellas! It was listed pretty cheap ($1250 with new interior) and was thinking that I have some stuff to barter for it. That is very good to know about the OMC Drives, I'm not looking for any more of a headache than owning a boat has to be. Just got done with a floor in a '84 16' Capri and would love to have the extra 3 feet that this one offers (19'er). Not to mention the V8 upgrade from the AQ125 4cyl thats in my current capri.

I'm in Colorado, so no worry about salt water..
Thanks again for taking the time to reply and pass along your knowledge and experience!!

Plenty of other boats out there. Just avoid anything with an OMC drive, Ford/Chrysler power, or a 3.7L/470 Mercruiser, and you're gunna be OK... ;)
 

ajax5240

Petty Officer 2nd Class
Joined
Aug 6, 2011
Messages
134
Re: 305ci Engine Replacement - Auto Block?

Rogers, the list of things to avoid is more helpful than what to look for. Thank you again for your help!

The avoid anything with Ford power almost goes without saying doesn't it? :lol:

Found On Reservoir Dead?
 

RogersJetboat454

Commander
Joined
Jul 9, 2010
Messages
2,964
Re: 305ci Engine Replacement - Auto Block?

Rogers, the list of things to avoid is more helpful than what to look for. Thank you again for your help!

The avoid anything with Ford power almost goes without saying doesn't it? :lol:

Found On Reservoir Dead?

It ain't a Swiss guy (Chevrolet), VS an Irish Guy (Ford), VS a German guy (Chrysler) debate...
All built equally reliable engines IMHO...

It comes down to the support of keeping each one's respective power offerings running in a marine environment.
Merc dropped Ford in the 70's, and never used Chrysler. Chrysler and Volvo had some ties, and Chrysler even dabbled in their own drives, but that's history from 30+ years ago. Volvo and OMC stopped using Ford in the 90's.
That leaves Chevrolet, and GM corporate which are still used today, meaning parts (manifolds, couplers, marine cooling, marine electrical) are plentiful and cheap.
 
Top