What size carb on LT1?

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Dec 28, 2004 | 01:52 PM

TJefferson2020

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From: Snake handler

What size carb on LT1?

What was the cfm of the Holley carb that came stock on the 1970 LT1?

Also, do you know the model number or part #?

Thanks!

Dec 28, 2004 | 01:54 PM

copter

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From: Savannah Ga

I had a brand new 1970 Z/28 and they came with the same carb I think.Holley 780cfm.Sorry don't have part#

Dec 28, 2004 | 02:25 PM

Tom73

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From: NM

Quote:

Originally Posted by pjmonfre

Also, do you know the model number or part #?

Two Holleys were used on the 70 LT1. One was Holley R4489A #3972123, it was used on the LT1 equiped with evaporative emission control. The other was Holley R4555A #3972121 used on all others.

Sorry but do not know the CFM.

tom...

Dec 28, 2004 | 03:38 PM

Gordonm

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From: Forked River NJ

They should be 780 cfm vacuum secondaries.

Dec 28, 2004 | 08:01 PM

stingr69

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From: Little Rock AR

The factory carb was rated at 780 CFM. I think it had 2 power valves which is uncommon on aftermarket Holley carbs. The early 3310-0 generic replacement had a lot of the same parts/butterfly size but with a different booster style but it was only rated 750 CFM.

-Mark.

Dec 28, 2004 | 09:28 PM

TJefferson2020

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From: Snake handler

Thanks, guys.

The reason I'm asking is that a while ago I bought from Holley a brand new carb that was supposed to be a direct replacement for the original carb - trouble is it's 830cfm and folks around here say that's too big...

I guess I need to call Holley and see what's up.