1970 LT1 question
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Heel & Toe
Joined: Jan 2007
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1970 LT1 question
Hi All - Would anyone know for a 1970 LT 1 what cfm and jet openings for the carb were? Another question for the same motor is the cam specs and exhaust manifold runner size?
Thank you very much!
JD
Thank you very much!
JD
Race Director
Joined: Dec 1999
Posts: 19,610
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From: Forked River NJ
The LT1 cars used a 780 cfm vacuum secondary Holley. It was a 4150 design. Not sure on the jet sizes but someone here will have the specs for the carb and cam.
The exhaust was a joke for these motors. They used 2 inch manifolds the went into a 2 1/2 pipe down stream. I measured my id of the pipes before taking them off and the yactually went down to 1 7/8 at one point. All 4 cylinders feeding into this. I now run a 1 3/4 primary pipe on my car. The stock exhaust really chokes these motors down.
The exhaust was a joke for these motors. They used 2 inch manifolds the went into a 2 1/2 pipe down stream. I measured my id of the pipes before taking them off and the yactually went down to 1 7/8 at one point. All 4 cylinders feeding into this. I now run a 1 3/4 primary pipe on my car. The stock exhaust really chokes these motors down.
Last edited by Gordonm; Jul 11, 2007 at 04:10 PM.
Racer
Joined: Apr 2005
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From: Virginia
Thread Starter
Heel & Toe
Joined: Jan 2007
Posts: 17
Likes: 0
THank you
The participants on this forum are the best! The tech at Edelbrock tried to sell me on a 650 CFM model 1806 which is a Edelbrock Thunder Series AVS. I mentioned that an LT might take a 750 cfm but he said it would bog down.
I had my 69 350 rebuilt to emluate an LT1. A mechanic put a 600 CFM carb (Edelbrock 1406) and the power was somewhat lacking. I called the machine shop and they said a 750 cfm was more to what was needed. I have Sanderson shorty headers which are 1 7/8. going to 2 1/4 chambered exhaust, Edelbrock 2101 dual plane intake, and a roller cam.
I had my 69 350 rebuilt to emluate an LT1. A mechanic put a 600 CFM carb (Edelbrock 1406) and the power was somewhat lacking. I called the machine shop and they said a 750 cfm was more to what was needed. I have Sanderson shorty headers which are 1 7/8. going to 2 1/4 chambered exhaust, Edelbrock 2101 dual plane intake, and a roller cam.
