2007 Mercruiser 4.3 w/ cracked block

[dizzyalpaca]

Hello folks!

I have a 2007 caravellle 217 with a 4.3 Litre Mercruiser. I purchased the boat with a cracked block.

I have been doing lot of research on swapping the engine with a 4.3 vortec automotive engine. Easy to purchase from auto wreckers (I will do compression test and what not first)
I will switch over my marine parts and swap the camshaft over from the boat engine I have.

I just have a couple questions:

1 - What years of the GM 4.3 will be compatible to directly swap components from the 2007 boat engine? I believe the 4.3 made changes in 1996 & 2002 and so im not sure if i need to use a 2003 and up 4.3?

2 - I read that truck camshafts will work fine. So I was wondering if anyone knew if the chevy astro vans have same cams as the blazers/sierra's?

 

[dave8311]

Brass freeze plugs also

 

[Scott Danforth]

Get a 1996-2013 4.3 and you are fine. 2014 and later are LT motors

You are only using the short block and heads. Core plugs, head gaskets, circulation pump all need to be replaced with marine. Then you buy new exhaust manifolds, and on the 4.3, most likely a new intake. (Check yours for cracks)

All the boat rotating electrics, front accessory drive, ignition and fuel system will get transferred over.

 

[dizzyalpaca]

Get a 1996-2013 4.3 and you are fine. 2014 and later are LT motors

You are only using the short block and heads. Core plugs, head gaskets, circulation pump all need to be replaced with marine. Then you buy new exhaust manifolds, and on the 4.3, most likely a new intake. (Check yours for cracks)

All the boat rotating electrics, front accessory drive, ignition and fuel system will get transferred over.

Thank you for the reply! I read that in 2003 GM changed the 4.3 and was the introduction of multi-point fuel injection and also more balanced cam shaft.

Does this matter? I just want to make sure I am getting the right motor to make life eaiser for swapping over..

 

[nola mike]

Thank you for the reply! I read that in 2003 GM changed the 4.3 and was the introduction of multi-point fuel injection and also more balanced cam shaft.

Does this matter? I just want to make sure I am getting the right motor to make life eaiser for swapping over..

You won't be using the fuel injection, you'll be using your fuel system and intake. Dunno what more balanced cam shaft would be. Also might not need new head gaskets or core plugs. My '02 blazer engine had brass plugs and composite head gaskets. Of course, you'd have to pull at least one head to confirm the gasket. Also, I'm guessing all of the '96+ engines had CPS sensors but not sure. Your engine probably needs it, my carbed motor didn't.

 

[dizzyalpaca]

You won't be using the fuel injection, you'll be using your fuel system and intake. Dunno what more balanced cam shaft would be. Also might not need new head gaskets or core plugs. My '02 blazer engine had brass plugs and composite head gaskets. Of course, you'd have to pull at least one head to confirm the gasket. Also, I'm guessing all of the '96+ engines had CPS sensors but not sure. Your engine probably needs it, my carbed motor didn't.

Wicked appreciate the info! I located a 4.3 vortec from a Chevy Astro van. I am wondering if I should try and find one from a blazer instead?

 

[dubs283]

I located a 4.3 vortec from a Chevy Astro van. I am wondering if I should try and find one from a blazer instead?

If the vintage of the astro is 2003-2005 it is the same long block as blazer/jimmy and 4wd s10/sonoma. GM ID is LU3.

LU3 was also used in 2002-2014 silverado/sierra

 

[dizzyalpaca]

If the vintage of the astro is 2003-2005 it is the same long block as blazer/jimmy and 4wd s10/sonoma. GM ID is LU3.

LU3 was also used in 2002-2014 silverado/sierra

Thanks! the one I located was a 2002 astro. Wondering if it would be better to find a 2003 or newer?

 

[dubs283]

the one I located was a 2002 astro.

Thats most likely an L35 and utilized vortec heads. I'd guess it'd be fine for the intake off the cracked block but as stated earlier you need to ensure the intake wasn't also freeze damaged

 

[Scott Danforth]

Thank you for the reply! I read that in 2003 GM changed the 4.3 and was the introduction of multi-point fuel injection and also more balanced cam shaft.

Does this matter? I just want to make sure I am getting the right motor to make life eaiser for swapping over..

No, as you will NOT be using any of the automotive fuel injection crap. you will be throwing all that away and stripping the motor down the the longblock and heads. nothing else bolted to the motor is kept. Nothing. Just the two cylinder heads, the cylinder head bolts and the shortblock.

see post #3

you even have to use your marine oil pan on the motor.

 

[dizzyalpaca]

Awesome info!

No, as you will NOT be using any of the automotive fuel injection crap. you will be throwing all that away and stripping the motor down the the longblock and heads. nothing else bolted to the motor is kept. Nothing. Just the two cylinder heads, the cylinder head bolts and the shortblock.

see post #3

you even have to use your marine oil pan on the motor.

Awesome info!! Thanks everyone.

I just located a 4.3 from a 2009 Chevy 1500. Can anyone confirm this engine will work the same?

And is there any difference in the block between a volva penta and a mercruiser 4.3?

 

[Scott Danforth]

both volvo penta and mercruiser used the 4.3 block and heads from GM

Cam, intake, exhaust, ignition, and accessories are different, however the long block will be fine.

your 2009 will work fine as there are minimal changes and it falls in the 1996-2013 window

 

[Bondo]

Awesome info!

Awesome info!! Thanks everyone.

I just located a 4.3 from a 2009 Chevy 1500. Can anyone confirm this engine will work the same?

And is there any difference in the block between a volva penta and a mercruiser 4.3?

Ayuh,..... Welcome Aboard,.... The long blocks are the same, the stuff bolted to the long blocks differ,....