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Ls1 408 or ls2 403

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Old Sep 21, 2016 | 08:34 PM
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Default Ls1 408 or ls2 403

Hey LS1 Forum,

I am at the point to buy a GTO and I am looking into two of them.
2004 LS1 408
and 2006 LS2 403 or 402 am not really sure

LS2 made 485rwhp
LS1 hasnt been tuned yet but owner said it should put more than 500rwhp

I really confused as I heard LS1 block is heavier or something
Both are N/A and im planning to put f1 pro when i buy one.

Someone help me please
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Old Sep 21, 2016 | 08:36 PM
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The 408 is a LQ9 or LQ4
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Old Sep 21, 2016 | 09:30 PM
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Im not really into chevies so I have no clue whats the different betweem both of them but i made a fast research and got two different answers. If it is about the block material the 408 is iron block. If it is about the pistons shape i have no idea .
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Old Sep 22, 2016 | 02:45 AM
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Originally Posted by G0at
Im not really into chevies so I have no clue whats the different betweem both of them but i made a fast research and got two different answers. If it is about the block material the 408 is iron block. If it is about the pistons shape i have no idea .
A 408 is normally a 4.030" bore and a 4" stroke. You can take an LS2 block out to 4.030", but usually a 408 is built using a 6.0L iron block. That would be the heavier block as the LS1/2 blocks are aluminum.

With an LS2 block, 4.005" bore is more common with the stock sleeves, which ends up being a 403 with the 4" stroke.

An LS1 can only go to about 3.905" on the stock sleeves, which would be a 383 with the 4" stroke.
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Old Sep 22, 2016 | 09:54 AM
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Originally Posted by KCS
A 408 is normally a 4.030" bore and a 4" stroke. You can take an LS2 block out to 4.030", but usually a 408 is built using a 6.0L iron block. That would be the heavier block as the LS1/2 blocks are aluminum.

With an LS2 block, 4.005" bore is more common with the stock sleeves, which ends up being a 403 with the 4" stroke.

An LS1 can only go to about 3.905" on the stock sleeves, which would be a 383 with the 4" stroke.
Hey,
Thanks for reply. Both cars already built. I just need help with chosing between them. Am not building
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Old Sep 22, 2016 | 04:57 PM
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Originally Posted by G0at
Hey,
Thanks for reply. Both cars already built. I just need help with chosing between them. Am not building
I understand that. You were confused about what engines were in them, were you not?

Originally Posted by G0at
I really confused as I heard LS1 block is heavier or something

Someone help me please
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Old Sep 28, 2016 | 05:46 AM
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Both could simply be incorrectly or falsely advertised as to the engine.

As everyone says...you ain't getting a 408 with an LS1 block unless it's been very heavily worked with new liners etc which would almost be pointless unless it was done over a decade ago before other options appeared.
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Old May 17, 2021 | 12:24 AM
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Originally Posted by G0at
Im not really into chevies so I have no clue whats the different betweem both of them but i made a fast research and got two different answers. If it is about the block material the 408 is iron block. If it is about the pistons shape i have no idea .
why are you here then ???
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Old May 17, 2021 | 01:01 AM
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Originally Posted by Robert Brown
why are you here then ???
He's not. He hasn't been here for 5 years, which is also how old this thread is.
Man I wish people would check post dates.
I notice most of this type are posting for the first (and often only) time.
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