1970 LS-6 Carburetor

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Bakerjn

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Joined Jul 26, 2006

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Discussion starter · #1 · Jul 28, 2006

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I am hoping someone out there has an answer for me. I have read many different books on this subject and want to restore an LS-6 1970 Chevelle to the correct specs.

What carb did the LS-6 have from the factory. Some books say:

* A Holley 780 cfm Series 4150 #3767477

Other books say:
* A Holley 780 cfm Series 4557 #3967477

And other books say:
* A Holley 800 cfm Series 4150 #3767477

Anyone got an answer?

 

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L7870_cortez

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Joined Apr 1, 2001

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620 Posts

#2 · Jul 28, 2006

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My Jan Built 70 LS-6 has a 4557. Different Carbs for Different Dates.
Mike

 

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d1_bradley

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Joined Sep 1, 1998

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3,409 Posts

#3 · Jul 28, 2006

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NHRA says 450 454 11.25 1-4 Holl 4491-1A/SM 4556-1A/AUTO Both are 4150 type. You will also see them referred to as 4492 and 4557 in restoration guides. These are the "list numbers" not the GM p/n that you show. I have seen both 780 and 800 also. The Holley site doesn't even list them...... Rich probably has more info.

 

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ProdigyCustoms

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Joined Mar 5, 2006

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751 Posts

#4 · Jul 29, 2006

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4557 is a 4 speed, 4492 is a auto, 4556 is a CA Emnissions auto, and 4493 is CA 4 speed emisions