Mercruiser 5.0 replacement

cjstimpson

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Jul 22, 2026
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Hi, I'm looking at replacing a 2008 Mercruiser 5.0 TKS using a long block and transferring components. How can I know if the long block I order is a fit? There's also a 5.7L which might be a fit as well, but it isn't clear to me whether any extra tuning is needed for the larger displacement, such as on the carburetor.

Any tips are appreciated!
 

Scott06

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Apr 20, 2014
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Hi, I'm looking at replacing a 2008 Mercruiser 5.0 TKS using a long block and transferring components. How can I know if the long block I order is a fit? There's also a 5.7L which might be a fit as well, but it isn't clear to me whether any extra tuning is needed for the larger displacement, such as on the carburetor.

Any tips are appreciated!
If it is a vortec long block 96 and newer it is identical to what you have. Good time to drop in a 5.7 which is externally identical. May have to reject the carb or step up to a 4 bbl edelBrock 1409.

I installed a partial engine from these guys in 2016 has worked excellent for over ten years now. Below is a 5.7 package with carb and intake will drop in and might have to go up in prop pitch 2” or so

 

nola mike

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Apr 22, 2009
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Might want to check out this thread:



 

Bondo

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Hi, I'm looking at replacing a 2008 Mercruiser 5.0 TKS using a long block and transferring components. How can I know if the long block I order is a fit? There's also a 5.7L which might be a fit as well, but it isn't clear to me whether any extra tuning is needed for the larger displacement, such as on the carburetor.

Any tips are appreciated!
Ayuh,...... Welcome Aboard,....... How did you come to the conclusion that you need a new/ rebuilt long block,..??..??
 

cjstimpson

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Jul 22, 2026
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Ayuh,...... Welcome Aboard,....... How did you come to the conclusion that you need a new/ rebuilt long block,..??..??
A mechanic diagnosed this for me and said a couple cylinders have too little compression. It overheated and I'm guessing the new impeller had problems.
 

cjstimpson

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Jul 22, 2026
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If it is a vortec long block 96 and newer it is identical to what you have. Good time to drop in a 5.7 which is externally identical. May have to reject the carb or step up to a 4 bbl edelBrock 1409.

I installed a partial engine from these guys in 2016 has worked excellent for over ten years now. Below is a 5.7 package with carb and intake will drop in and might have to go up in prop pitch 2” or so

Thanks for the link. And for the tips about the carb and prop. I was looking at perhaps getting this one.

 

alldodge

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With the overheat and a blown head gasket, most likely all you need is a new head gasket
 
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