Carb advice
Thread Starter
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Joined: Nov 2015
Posts: 78
Likes: 4
From: St. Louis
Carb advice
I rebuild my 1970 350 out to a 383, added headers and 2 1/2 exhaust. I plan to rebuild my Quadrajet. I discovered that it is from a 1972 350. Is this carb ok to keep and do I need to change the jets?
Thanks
Thanks
Pro
Joined: Nov 2015
Posts: 600
Likes: 110
From: Mainz
I had my original Q-Jet rebuild by Lars to match my 71 L48 383 build. It runs perfect, and AFR is in every driving condition right on the spot. I have AFR sensor bungs welded in each side of my exhaust System, and got a LM2 to check. It is really perfect. He is the specialist for These carbs.
Le Mans Master
Joined: Mar 2001
Posts: 5,741
Likes: 646
From: Lincoln, CA
Not sure how anyone tuned a carb without an LM2 LOL.
Lar's set my QFT for me. Idle was perfect but the rest was super rich. Still adjusting it a little at a time.
Idle is now 14.5, around town 13.1 and cruise is till a fat 12.5.
Lar's set my QFT for me. Idle was perfect but the rest was super rich. Still adjusting it a little at a time.
Idle is now 14.5, around town 13.1 and cruise is till a fat 12.5.
Race Director
Joined: Oct 2008
Posts: 19,295
Likes: 1,681
From: Long Island
It's a fine carb but hard to properly tune.
I would go with a spread bore Holley as a second choice
I would go with a Weiand street warrior manifold painted orange with an Edelbrock thunder carb as my first choice, I did on my 71 and was pleased as was the engine builder when he dyno tuned it. Out of the box it was almost perfect... I did not paint mine as I needed the LT1 look.
The manifold has a 3.65 carb height - very close to stock. The performance is much improved.
I would go with a spread bore Holley as a second choice
I would go with a Weiand street warrior manifold painted orange with an Edelbrock thunder carb as my first choice, I did on my 71 and was pleased as was the engine builder when he dyno tuned it. Out of the box it was almost perfect... I did not paint mine as I needed the LT1 look.
The manifold has a 3.65 carb height - very close to stock. The performance is much improved.
Last edited by BLUE1972; Apr 8, 2016 at 06:13 PM.
Had a 1976 L-82, 4-sp
Joined: Mar 2011
Posts: 5,338
Likes: 1,213
From: Some days your the dog and some days your the hydrant.
Royal Canadian Navy
To answer your question - yes, keep the carb and you may need to tune it for your setup e.g jet changes. You need to check your plugs after running a few hunderd miles for colour - tan is ok, white is lean - to see if its running rich or lean but no guarantees it will be correct with today's gas formulations.
Drifting
Joined: May 2012
Posts: 1,353
Likes: 44
From: Calgary Alberta
I have quadrajets on both of my manual transmission C3s, and they work very well. The quadrajet is a better carb than most. Just rebuild yours and look at re-jetting if necessary--you'll likely be a bit lean. If you email Lars, he'll give you a copy of his tuning papers. Those should get you where you want to be.
Last edited by Brcmpbl; Apr 8, 2016 at 10:44 PM.
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