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How much compression?

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Old Dec 30, 2016 | 11:43 AM
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Default How much compression?

I am thinking about buying a fresh 408 stroker from a guy. He said the following
aluminum 6.0 bored 30 over, eagle 4.000 crank, 6.125 howards rods, and diamond +10 pistons.

goals are street truck (s10)
Currently stock ls1 on 150 shot
Want to put this 408 together with the 799 heads I got and a 228/232 cam and two kits probably 250 shot.

what compression ratio am I looking at?
what would yall do?
h/c/i lts and nitrous.
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Old Dec 30, 2016 | 12:31 PM
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Originally Posted by blacknyellow
I am thinking about buying a fresh 408 stroker from a guy. He said the following
aluminum 6.0 bored 30 over, eagle 4.000 crank, 6.125 howards rods, and diamond +10 pistons.

goals are street truck (s10)
Currently stock ls1 on 150 shot
Want to put this 408 together with the 799 heads I got and a 228/232 cam and two kits probably 250 shot.

what compression ratio am I looking at?
what would yall do?
h/c/i lts and nitrous.
Gonna need more info to determine compression ration but nitrous loves compression, What cc are the heads what head gasket thickness, how far are piston out of the whole to be able to come up with compression.
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Old Dec 30, 2016 | 12:33 PM
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Diamond sells forged Nitrous LS pistons.

The 408 pistons with a 10cc dome designed for LS6 heads are part number 11565.
These 10cc pistons with a 64cc chamber (799/243 heads) puts compression around 13.6:1.

With 317 or LS3 heads, compression is around 12.5:1.
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Old Dec 30, 2016 | 12:44 PM
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You can't bore an aluminum block .030 over.
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Old Dec 30, 2016 | 12:53 PM
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Originally Posted by farmington
You can't bore an aluminum block .030 over.
Technically you can, there isn't anything stopping you.
Its been done a few times with some success. I don't know how well it would go with 13:1 and nitrous.
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Old Dec 31, 2016 | 10:21 AM
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I thought it was only the la1 block that couldnt be bored much. Should I be concerned about sleeve thickness?
stock thickness fel pro gasket is what i've got.
the motor is in pieces new in box, just needs to be put together.
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Old Dec 31, 2016 | 01:11 PM
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Dude said it has darton sleeves is there any way ro tell by looking at them? They are brass colored
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