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#1 |
Canadian Trucker
Join Date: Nov 2010
Location: Sarnia, ont canada
Posts: 648
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quadrajet?
I'm in the middle of putting a quadrajet back on my truck, it had a holley on it when I got it. Please don't tell me to keep the holley, it's a piece of ****. Anyway my question is in this pic there is a fitter on the back of the carb, whats it for? It's on the bottom at the base plate.
![]() Do I need to plug it? What was it for, the holley didn't have anything like it.
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#2 |
Registered User
Join Date: Jul 2007
Location: Sims, NC
Posts: 531
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Re: quadrajet?
vacuum port for your power brake booster.
Mike
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All things Chevy truck: 1986 SWB "Jolene" boosted 5.3/4l80e project |
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#3 |
Canadian Trucker
Join Date: Nov 2010
Location: Sarnia, ont canada
Posts: 648
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Re: quadrajet?
Ok, thanks.
My booster vacuum is coming from the intake itself so can I just block this off, or would it be better to hook it back up to the carb?
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#4 |
Registered User
Join Date: Jul 2007
Location: Sims, NC
Posts: 531
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Re: quadrajet?
It's fine the way you have it, just block off this port.
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All things Chevy truck: 1986 SWB "Jolene" boosted 5.3/4l80e project |
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#5 |
Just here to tinker
![]() Join Date: Jun 2008
Location: Holland, MI
Posts: 3,692
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Re: quadrajet?
Glad to see your going with a Q-jet! It is a very misunderstood carb because of it's temperament but when it is tuned just right for the right application, what an amazing carb!
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#6 |
All About the BOWTIE
Join Date: May 2010
Location: Los Banos, California
Posts: 436
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Re: quadrajet?
x2 on that.. I have a quadrajet m4me.... that I got pretty much all tuned in... vacuum gauged it, and pulling about 18-21 in vacuum. It hums along nice... and I get about 15-18 mpg highway.
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CaliDude76 ![]() "... Being "SQUARE".. is where it's at...." ![]() Proverbs 15:30 .... "A Cheerful look brings joy to the heart, and good news gives health to the bones..." Be exceedingly blessed today, my friends!... |
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#7 |
Canadian Trucker
Join Date: Nov 2010
Location: Sarnia, ont canada
Posts: 648
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Re: quadrajet?
So I've had this carb on for about a week now, and I can't believe the difference. That Holley was junk, I've picked up more throttle response, better response, and my fuel economy went up from 4-5mpg to 9-10 easy. Now I know alot of that has to do with the fact that the holley was in need of a rebuild (it just poured the gas into the cylinders), but I think some of it has to do with the quadgrajet being better suited for the job.
And thank you guys for the help. I ended up running the brake booster line into the back of the carb afterall. Because it was easier to find the parts to run it, then it was to find the parts to plug it. The truck is back up on all fours and runnin like a champ
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