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-   -   1980 Quadrajet (https://67-72chevytrucks.com/vboard/showthread.php?t=259674)

dan42 09-23-2007 11:24 PM

1980 Quadrajet
 
1 Attachment(s)
I checked the numbers on the Quadrajet that is on the motor I'm gonna put in my '67, (a 350) and found that it was built in late '79, with California emissions, and was for a manual tranny (I'm gonna run a 4-speed). The P.O. said the motor ran great, but I never heard it. It was in a '79 Blazer, so it had to be smogged from time to time here in California. It is worth leaving on the motor and seeing how it runs, or swapping it out now? I'm not sure how much the smog stuff will actually affect the carb. :confused: Thanks in advance.

dan42 09-24-2007 09:59 AM

Re: 1980 Quadrajet
 
ttt

woodridge 09-24-2007 10:04 AM

Re: 1980 Quadrajet
 
I don't see any reason not to run it. You may need to re-jet it or change the power valve spring but it still just mixes air and fuel.

StingRay 09-24-2007 10:13 AM

Re: 1980 Quadrajet
 
The 79-80 q-jets were the best q-jet for all around performance and drivability. They are THE years to rebuild and use. They had them pretty well sorted out and then went on to those computer controlled q-jets and then efi. I personally sought out just that same carb to rebuild and use. A slightly better choice comes off of a 79-80 Z28 or vette.

WorkinLonghorn 09-24-2007 10:19 AM

Re: 1980 Quadrajet
 
Does it have idle mixture screws? That was one of the smog carb changes (we're talking California here);you couldn't adjust the idle unless you drilled out a plug or removed a limiter cap,but I'm not aware of any other negative aspect to these carbs.They were part of the CCS (Controlled Combustion System) which set a leaner mixture,higher engine operating temperature,and heated (100F) air intake.
I think I'd try it out and see how it works before deciding.

StingRay 09-24-2007 10:33 AM

Re: 1980 Quadrajet
 
I guess I should qualify that yes the idle air caps were removed and the jetting and rods/spring were optimized in my rebuild. It's the best core to build from though. The electric choke is a big plus for carb retrofitting too.

dan42 09-24-2007 12:35 PM

Re: 1980 Quadrajet
 
Thanks for the good info, guys. I'll clean it up and see what it does.

passthebuck 09-24-2007 01:52 PM

Re: 1980 Quadrajet
 
StingRay is right - In terms of QJets, those are the best. I have a few that I've nabbed for future projects. A rebuild, new throttleshaft bushings & knock those plugs out & its a great carb.

steveshow 09-24-2007 02:40 PM

Re: 1980 Quadrajet
 
Ditto to PASSTHEBUCK. These carbs are hard to beat for a street truck, and can be made to run on the strip. THey offer better economy than Holley or other square flange carbs, and really go when those big secondaries open up. Keep a good fuel fliter on them and they will outlive you. There is a book on modifying these "Modifying Quadra jet carbs " or something to that effect, I have had it for yrs, forgot where I got it but I think they are on AMAZON.COM now. The book is worth its weght in gold.

forgeman 09-25-2007 08:11 PM

Re: 1980 Quadrajet
 
Rebuilt it! We have the technology we can make it better stronger faster. You will need the serial numbers off it or even better take the husk in with you to the auto store for a rebuild kit. (Get the correct one they can NOT be returned once opened.)

Give your self plenty of time and an organized workbench. The secret: it is easy if you take your time and have a "clean" area.

This is the rebuild of a 71 Rochester QuadraJet.


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