Edelbrock 600 CFM (#1406) to replace stock 79 L-48 Quadrajet? - Corvette Forum

Go Back   Corvette Forum > C3 Corvettes, 1968 - 1982 > C3 Tech/Performance
Log In 
Register FAQ Search Today's Posts Mark Forums Read Vendor Directory

C3 Tech/Performance
V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette Sponsored by

Edelbrock 600 CFM (#1406) to replace stock 79 L-48 Quadrajet?

Thread Tools Search this Thread
Old 02-28-2012, 03:54 PM   #1
Neo Fender
CF Senior Member
Member Since: Mar 2001
Posts: 1,409
Location: St. Louis, Missouri
Thanks: 0
Thanked 0 Times in 0 Posts
Default Edelbrock 600 CFM (#1406) to replace stock 79 L-48 Quadrajet?

My original Carter (yes Carter) Quadrajet still causes the idle to be a little high. It may be the ubiquitous butterfly shaft leak (bushings). I have an Edelbrock 600 CFM carburetor. Will it fit and be worth the effort or should I fix the Q-jet?

* Original manifold
* Quadrajet-spread bore (IIRC), Edelbrock-square bore (bolt pattern?)
* Throttle linkage?
* Automatic transmission kickdown?
* PCV, EGR, Power brake booster, vacuum advance, etc.?

Neo Fender is offline   Reply With Quote
Old 02-28-2012, 04:00 PM   #2
CF Senior Member
MelWff's Avatar
Member Since: May 2006
Posts: 6,289
Location: Danbury CT
Thanks: 0
Thanked 21 Times in 21 Posts

Fix the Quad. Squirt some carb cleaner on shaft and see if idle changes to confirm your thought.
MelWff is offline   Reply With Quote
Old 02-28-2012, 05:36 PM   #3
CF Senior Member
7T1vette's Avatar
Member Since: Jan 2006
Posts: 24,810
Location: Crossville TN
Thanks: 0
Thanked 23 Times in 22 Posts

Unless someone has drilled holes in the primary throttle plates of your Q-Jet, there is no reason that you can't get the idle to adjust where you need it, unless the linkage is sticky or the carb is not adjusted properly. I have known of carbs that are not placed 'centrally' on the intake, causing the throttle plates not to close completely. That's fixed by loosening the 4 attaching bolts and wiggling the carb into a more central position, then retightening to specifice torque.

I would tend to agree that rebuilding/adjusting your original Q-Jet is likely the best way to go. And it certainly will be the least expensive of your choices. Before you reinstall it, make all carb and choke adjustments per the Chevrolet Chassis Service Manual for your year car.
7T1vette is offline   Reply With Quote
Old 02-28-2012, 08:53 PM   #4
Oldguard 7
CF Senior Member
Oldguard 7's Avatar
Member Since: Apr 2002
Posts: 2,182
Location: Norfolk VA
Thanks: 0
Thanked 2 Times in 2 Posts

I agree with the others. Get the q jet rebuilt. I bought the. Edel 1406 carb and like a dummy I gave away my qjet to my instructor while in auto tech school. I should have known something was up when his face lit up as I handed it to him. As for the 1406 carb, I bought the edel 2101 manifold so I wouldnt have to buy an carb adapter plate. I have not have had problems with it as it still sits atop my engine. But is is not a performance carb. If I can stop being lazy, I will replace that manifold/carb combo with a Stealth manifold and a 750 mighty demon carb (both new in box a few years ago)
Oldguard 7 is offline   Reply With Quote
Old 02-29-2012, 07:53 AM   #5
CF Senior Member
jb78L-82's Avatar
Member Since: Oct 2007
Posts: 3,875
Thanks: 0
Thanked 7 Times in 7 Posts

I agree with others that fixing the OEM Qjet would be the best bet. I replaced my Qjet with a Holley 4175 650 Spreadbore replacement in 1985 and it has been perfect (just rebuild it myself about 1 year ago and running great again) but like oldguard7 let a buddy of mine "borrow" my OEM Qjet to run on his built Pontiac 400 in an 80 Trans AM in the 80's, engine backfired through the carb catching the carb on fire (I was not there at the time) destroying the carb-I am still pissed at him for that blunder! Never saw my OEM Qjet again-Knowing what I know now, I sure wish I still had it and would have at least tried to get it in running perfectly, even if I didn't use it on the car.

Last edited by jb78L-82; 02-29-2012 at 07:57 AM.
jb78L-82 is offline   Reply With Quote
Go Back   Corvette Forum > C3 Corvettes, 1968 - 1982 > C3 Tech/Performance
Reload this Page Edelbrock 600 CFM (#1406) to replace stock 79 L-48 Quadrajet?

Similar Threads
Thread Thread Starter Forum Replies Last Post
1958 Carburetor Options Dads58Vette C1 & C2 Corvettes 2 04-02-2015 08:50 AM
Edelbrock 1406 needs spacer mcb55-210 C1 & C2 Corvettes 8 05-31-2014 06:21 PM
Carter WCFB Replacement Choices C2 LintonLLC@Gmail.com C1 & C2 Corvettes 4 01-26-2010 02:53 PM
Edelbrock Q-Jet vs Edelbrock perfomer carb Topas C3 Tech/Performance 17 04-22-2003 01:03 PM
850 CFM carb? JoeMacgruder C3 Tech/Performance 7 04-18-2002 06:56 PM

1973, 79, carb, carter, cfm, change, corvette, edelbrock, edlebrock, qaudrojet, quadrajet, replace, replacement, vacuum, vette, whats

Thread Tools Search this Thread
Search this Thread:

Click for Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Forum Jump


All times are GMT -4. The time now is 09:35 PM.