73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Performance => Topic started by: Jason H on November 19, 2007, 05:29:07 pm
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I have a 1981 Scottsdale 3/4 ton 2wheel drive. 350 ci. Would like to replace the failing stock carb with reasonable price upgrade. Any suggestions?
Jason.
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How about rebuild the Q-jet that is on it?
BTW, welcome to the site!
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A < 600 cfm holley w/ vacuum secondaries is what I'd suggest..I hate q-junks.
A street Predator would be better, but they're expensive and rare.
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I say a nice rebuilt Q-jet is hard to beat. my second choice would be a 570 Holley street Avenger, but that would require a differant intake, or a crappy adapter
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Welcome to the site Jason H.
Your gooing to get a mix bag of responses and preferences. I have heard from alot of guys the Q-jet is a pretty good carb for street use and some mild performance motors.
I had a Q-jet on a stock motor and worked great. I now have a mild performance 355ci with an RV cam Edelbrock Performer EPS and an Edelbrock 600cfm 1406 carb. I am moderately pleased with mine.
As far as my experience and little knowledge, I understand that with an Edelbrock you get pretty decent performance with a little economy at the pump. With a Holley it is infinitely adjustable, a great performer, a little more difficult to tune (in some cases) and less economical gas mileage wise. Unless its tuned down.
It all depends on your motor setup. I have also seen where guys put on too big of a carb and does not perform to expectations, so dotn over carb your motor.
I am currently at 300hp with 325 ft lbs torque. If I want a little more cam and better flowing heads I would have to spring for something in the 700-750 cfm range.
Hope this helps, happing hunting!
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welcome aboard! now, with that being said...i'm more an Edelbrock guy myself. yea, you'll get more all-out performance with a Holley, but they require constant tuning to keep the engine running good. the Edelbrock carbs tend to be a "set-and-forget" carb. they are both really good carbs though...if you like tuning your stuff, then get the Holley...it will give you better performance...
but if you get your Q-Jet rebuilt and tweak it a little bit you would be amazed at the performance it can give you...along with some decent fuel economy that the Holley and Edelbrock WON'T give you
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You know edelbrock makes qjets now,right? My vote is cast....Quadrajet.
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If Im correct, Edelbrock has dropped the Q-jet in favor of the AVS style carb.
As far as Holleys needing constant tuning, Ive got a 770 Holley on mine that hasent been touched in 3 years. Its whatever works for you, I personally find Holleys to be less troublesome & more consistant.
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I vote for the Q-jet. Small primaries for everyday driving, but large enough secondaries for performance. GM engineers did a good job with the carburator. Just my .02
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I guess it comes down to what you've had the best luck with..The q-jet on my truck now is the only one that hasn't caused me endless problems, no matter if its been rebuilt or not...My race predator worked ok for a daily driver, but without a choke or idle circuit, it had its querks..A street predator is the same as a race version, but with an idle circuit and provisions for a choke..Predators are NOT an economy carb, but my dad's '78 cadillac got much better city mpg with my race predator on it compared to his q-jet..
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Edelbrock no longer sells the rebadged Q-jets. The company that supplied them still sell them, but I don't remember under what label or what their name was. Probably can search the forum, I put it here somewhere...
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Every experience I've had with Q-jets has been horrible. Rebuilding one is a bear.. and if you do rebuild, the chances of it working 100% is not always the case, Q-Jets are VERY temperamental. I would suggest to just replace the intake with a Edelbrock performer, you can get them for 50 bucks used usually, and a 600 CFM Holley. Edelbrocks are nice, but they remind me of Quads to much.. Holleys are very user friendly to work on aswel.
But if your in a pinch on money, then just try and rebuild it for now, later on try what I said, you won't regret it. ;)
EDIT: Or just get a spread bore holley. Perfect for everyday driving, and also user friendly, like all Holleys.
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Quadrajets are not that difficult. There's a zillion websites and rebuilding manuals out there to help even the least knowledgable person rebuild it for under $50 bucks. Unless the throttle shaft is wasted rebuild your Q-jet and spend some time checking and setting everything nice. Q-jets do provide good performance and good daily driving economy. Seal up the casting wells on the bottom of the carb with some epoxy. Make sure the choke breaks are working good and really all you'll have to do is set your choke, fast idle and curb idle.
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You know edelbrock makes qjets now,right? My vote is cast....Quadrajet.
yea, like was mentioned above, they don't anymore. but if you find a used one, then yea, you have a QJet...and they can get great economy...