1988 OMC 4.3L Engine block change help?!

O

Ochoa

Cadet
Joined
Oct 28, 2012
Messages
11
Hi guys,

I have a 1988 Sunbird Eurosport with a 4.3L OMC/GM V6.

The block has a Giant crack (previous owner) but everything else is in great condition.

I have already stripped the engine down to the block. I am now in search of a used block (junkyards Ect...)

My question:

Does anyone have any idea what GM vehicles have the same base block?

I know ill need to change out a few things like the cam and freeze plugs and what not, but its my understanding that the block from OMC was a standard (marinized) GM block that was used in multiple other vehicles like the blazer, jimmy, S10, and so on...

Has anyone done this? Any specifics would be a great help!

Thanks!
Chris,
 
Bondo

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,525
Re: 1988 OMC 4.3L Engine block change help?!

GM block that was used in multiple other vehicles like the blazer, jimmy, S10, and so on...
Click to expand...

Ayuh,.... Yer life will be much easier, if ya can find another 1988...
 
bruceb58

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,478
Re: 1988 OMC 4.3L Engine block change help?!

To add what Bondo said, In 1992 or thereabouts, a balance shaft was added to the 4.3L so the intake manifold changed. If you went with that type engine, you would have to find an intake manifold for a carb as engines out of vehicles will have a manifold for injection. Older models of engines would have the 2 piece rear seal.
 
O

Ochoa

Cadet
Joined
Oct 28, 2012
Messages
11
Re: 1988 OMC 4.3L Engine block change help?!

Bond-o said:
Ayuh,.... Yer life will be much easier, if ya can find another 1988...
Click to expand...

So im looking for a 1988-1991 GM 4.3, preferably a 1988? Do you know what vehicles that came in?

What kind of issue might I run into if I dont find a 1988?
 
O

Ochoa

Cadet
Joined
Oct 28, 2012
Messages
11
Re: 1988 OMC 4.3L Engine block change help?!

bruceb58 said:
To add what Bondo said, In 1992 or thereabouts, a balance shaft was added to the 4.3L so the intake manifold changed. If you went with that type engine, you would have to find an intake manifold for a carb as engines out of vehicles will have a manifold for injection. Older models of engines would have the 2 piece rear seal.
Click to expand...

So am I right in saying that im looking for 1988-1991 GM 4.3L and that can be found in vehicles like a jimmy or S10?

I have to replace the intake since mine is cracked as well, so because of that, does that widen my options?
 
bruceb58

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,478
Re: 1988 OMC 4.3L Engine block change help?!

Ochoa said:
I have to replace the intake since mine is cracked as well, so because of that, does that widen my options?
Click to expand...
Might as well get as new as possible then and get one with Vortec heads. 96 or newer. Make sure you check availability of intake manifolds for the carb you are using.
 
O

Ochoa

Cadet
Joined
Oct 28, 2012
Messages
11
Re: 1988 OMC 4.3L Engine block change help?!

bruceb58 said:
Might as well get as new as possible then and get one with Vortec heads. 96 or newer. Make sure you check availability of intake manifolds for the carb you are using.
Click to expand...

So just to clarify, if i can find a newer block with the vortec heads, will my marine exhaust manifold still bolt up correctly? Along with that, is the bell housing bolt pattern the same? Starter? And so on...

My original plan was to use the same cam shaft from the old block in the new block because I was told that they are different (auto vs marine)

Obviously I would need a new intake that will suite a carb as well.
 
bruceb58

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,478
Re: 1988 OMC 4.3L Engine block change help?!

The exhaust will be the same. 90% sure the starter and flywheel is the same so need to check for sure on that.

If the engine comes out of a truck, which most 4.3s are, that cam will be fine.
 
You must log in or register to reply here.
Top