Gen V Heads HELP!
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Gen V Heads HELP!

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    Default Gen V Heads HELP!

    Does anyone know what heads came on a 08/92 production 7.4 Carb, 300hp. Bravo1 ? Mercruiser said Oval Port but couldn't say which ones. Should they be "peanut ports" or larger Oval. I would like to switch out to 049's. Will this Gen V support or is the compression going to be a problem?
    Thanks

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    Quote Originally Posted by Carrera J View Post
    Does anyone know what heads came on a 08/92 production 7.4 Carb, 300hp. Bravo1 ? Mercruiser said Oval Port but couldn't say which ones. Should they be "peanut ports" or larger Oval. I would like to switch out to 049's. Will this Gen V support or is the compression going to be a problem?
    Thanks
    049s are a MkIV head and will not work on a GenV block. There will be a mismatch in the cooling passages at the lifter valley side of the deck.

    http://www.strokerengine.com

    Click the link, go to the Big Block Chevy section and scroll all the way to the bottom and it will show you the difference between the cooling passages between a MkIV and a GenV.

    I think I remember hearing about a company that might make a special head gasket that will adapt a set of MkIV heads to a GenV block, but the experts may wanna chime in on that one.
    Last edited by Jetaholic; 07-27-2009 at 01:53 PM.



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    Thanks, I thought that I heard before that the Gen V was a different set up.

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    Quote Originally Posted by Jetaholic View Post
    049s are a MkIV head and will not work on a GenV block. There will be a mismatch in the cooling passages at the lifter valley side of the deck.

    http://www.strokerengine.com

    Click the link, go to the Big Block Chevy section and scroll all the way to the bottom and it will show you the difference between the cooling passages between a MkIV and a GenV.
    except for one obscure sentence that seems out of place and doesn't make much sense, this guy is talking about Gen 5/6 heads on Mark 4 blocks, not the other way around.

    Mark 4 heads fit all blocks, 4/5/6

    take a look at all the aftermarket heads, and see what design they use.

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    Quote Originally Posted by 5325user View Post
    except for one obscure sentence that seems out of place and doesn't make much sense, this guy is talking about Gen 5/6 heads on Mark 4 blocks, not the other way around.

    Mark 4 heads fit all blocks, 4/5/6

    take a look at all the aftermarket heads, and see what design they use.
    I stand corrected. I was wondering about that...as I looked at the pics of the GenV deck it looked to me like a MkIV head should work on a GenV block, but I could definitely see how GenV heads would absolutely NOT work on a MkIV block.



    Quote Originally Posted by HammerDown
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    Well I am putting in a nice stereo system in the Carrera...maybe Ill put on some rap and turn the scoop sideways

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    Quote Originally Posted by Carrera J View Post
    Does anyone know what heads came on a 08/92 production 7.4 Carb, 300hp. Bravo1 ? Mercruiser said Oval Port but couldn't say which ones. Should they be "peanut ports" or larger Oval. I would like to switch out to 049's. Will this Gen V support or is the compression going to be a problem?
    Thanks
    If the ovals on the 7.4 are the Vortec, I believe they have 100cc chambers, where the 049's will have 119cc so by swapping, you'll lose compression.
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