truck long block vs marine long block

Cptkid570

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Oct 18, 2005
Messages
967
Hi everyone,
As I start my project of replacing the engine in my 1985 Searay (mercruiser 260), I think you will be hearing a lot from me. (I’ve already pulled my engine)

In shopping for the replacement engine, I found the best deal for a remanufactured marine chevy 350 long block is through either Rapido Marine or Power Source Distributors – both in Miami, both could have the reman engine delivered to my door for around $1500.

Now, I was at a local auto parts store (Autozone) and found that they have a reman chevy 350 long block (truck engine – also has 4 bolt main) for $1,004.99. I know that the truck engine is close enough to the marine specs to work.. and the truck engine already comes with brass freeze plugs, so, it would only need the marine head gaskets ($20 each) to make it work for marine. It wouldn’t be that much work to change the head gaskets since the bolts are now and not all rusted up. So, in thinking out loud, wouldn’t it be a better deal to just buy the truck engine and change the head gaskets to marine? Or am I missing something? And, I don't know if Rapido uses a true marine 350 chevy specs or if they are just truck engines also..

Thank you in advance your any opinions....
 

mkast

Lieutenant Commander
Joined
Nov 6, 2002
Messages
1,934
Re: truck long block vs marine long block

Verity the head gaskets are composite, no need to change them.
Cam specs should be close enough that you'll never know the difference. Check lobe separation angle.
What is the compression on the Autozone engine?
Does this engine come with a build sheet?
 

WillyBWright

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Dec 29, 2003
Messages
8,200
Re: truck long block vs marine long block

You should also put in a marine cam. It's not a question of performance, but timing. Marine cams are timed a little differently to prevent drawing exhaust water back in thru the exhaust valves. Trucks don't have that concern.

Make sure it has a high volume oil pump and you'll want to put a marine water circulating pump on. An automotive pump will rust (plain steel shafts). By the time you get all that, you're still not far shy of $1500.

Will they guarantee the truck block in a boat? That would be another very important question.
 

Haut Medoc

Supreme Mariner
Joined
Jun 29, 2004
Messages
10,645
Re: truck long block vs marine long block

I have heard good things about Rapid-O.....:)
 

Bondo

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Apr 17, 2002
Messages
71,095
Re: truck long block vs marine long block

Verity the head gaskets are composite, no need to change them.
Ayuh,......

The Only Thing that would concern Me would be the Circulating Waterpump mentioned by Willy........

Everything Else that comes in a Truck Long Block will Run Just Fine in a Boat.......

I haven't looked in awhile,...
But,....
GM Goodwrench Crate Motors weren't far from the Price you're looking at from Rapid,....
And That's a Brand New, Not Rebuilt motor.......
 

Cptkid570

Ensign
Joined
Oct 18, 2005
Messages
967
Re: truck long block vs marine long block

I would definitely use a marine water pump. I already have one on my motor that I'd transfer to the new motor (if I don't buy a new one).
 

delsol

Senior Chief Petty Officer
Joined
May 27, 2002
Messages
749
Re: truck long block vs marine long block

well i live in pa. went to rapido marine in south fla. got motor . waiting for local dealer to install it here with install with extended watt. $300 you get 2 yrs with i think 4k labor and parts. but boat dealer must install. at rapido raul gives you one year...but i would think autozone or gm would give you zero in a boat...
cam is different i heard. so is oil pump.
but i got a gm 350 4 bolt from a gm parts plus dealer a few years a ago (car motor) for my buddy it still runs..
its a nice engine. but i have not heard it run yet..but at his shop i heard one run right on the floor getting ready to go in ..it sounded really good
bob/philly
 

whywhyzed

Banned
Joined
Feb 1, 2005
Messages
1,871
Re: truck long block vs marine long block

Any Warranty beyond 30 days would be the least of my concerns... If it makes it that long it was built right.
If it fails 12 or 16 months later they ain't going to honour any warranty anyways... unless you buy 50 motors a year from them or something....
I can't think of a scenario where a motor would fail 2 years after install and be the fault of the rebuild...
 

I/O WALDO

Petty Officer 1st Class
Joined
Nov 16, 2005
Messages
320
Re: truck long block vs marine long block

What is yall's opinion o Jasper Marine engines?
 

8AteEight

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May 23, 2005
Messages
79
Re: truck long block vs marine long block

....Hmmmm. Im not sold on the "checker/autozone" engines, tho. I was in class (auto-mechanics) And I counted more than a few that were not built right. After pulling the pistons out, we found out they had bored each hole different: like #1 was +10, 2 was standard; 3 was +40, and 4 was +10.

Maybe we got some freak accidents, but there sure were a lot of em.
 

whywhyzed

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Messages
1,871
Re: truck long block vs marine long block

8AteEight said:
....Hmmmm. Im not sold on the "checker/autozone" engines, tho. I was in class (auto-mechanics) And I counted more than a few that were not built right. After pulling the pistons out, we found out they had bored each hole different: like #1 was +10, 2 was standard; 3 was +40, and 4 was +10.

Maybe we got some freak accidents, but there sure were a lot of em.

I would believe that... I know a place that built Cat 3208's for years, and selected pistons based on the casting number underneath. They didn't realize there were different crown heights for different compression ratios and turbo vs. NA etc...They built engines for 3 or 4 years with all different compression ratios throughout the 8 holes.... You wanna see white smoke at start up.... 3208's are bad enough cold smokers when they are assembled correctly... these were eyeball burners
 

delsol

Senior Chief Petty Officer
Joined
May 27, 2002
Messages
749
Re: truck long block vs marine long block

yes we got a local company here . recon. my buddy used to work thier. i dont like lot's of thing's about these places. lots of people are just on the line producing. vrs a rebuilt shop knowing about motors.....as far as jasper. my buddy brought a inline chev 6 . had it installed and it was making weird noise. after the engine was replaced he got 8 years or so out of the second one with toatl perfect care to this motor . but no more then 60k in miles. so i wont buy a jasper because of this. he had the motor redone by an engine shop 2 yrs ago. perfect..he loves his old chev.
bob
 

Flukinicehole

Petty Officer 1st Class
Joined
May 29, 2004
Messages
365
Re: truck long block vs marine long block

All reman factories are the same. If you want a good engine you have to have one built by a machine shop.They do still exsist and can be a little more expensive but are better then any of the factories out there. Even the new GM crate engines are not what they used to be. Talk to a real machinist and he or she will tell you the same.Basically you roll the dice when repowering.It`s sad but true.
 
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