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Good info! I've got a 1968 Jeep Gladiator with a Quadra-jet on a 350 SBC. I've let it sit too long and the carb is gunked up.
It has the divorced automatic choke which never worked right. Been looking to replace with a QJ using manual choke so I can control cold starts.
Been looking for a chart showing QJ carb numbers for specific auto brand/model/engine/trans applications to be able get one rebuilt that somewhat matches my application. Does anybody here know of such an application chart?
Last edited by Dumdum; 04/02/22.
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Campfire Ranger
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Campfire Ranger
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Had about 15 nice 67 to 72 Chev and GM trucks here for 25 years (all SB and BB V8s) - still have several - and have fought serious ethanol problems. Foolish enough to try to do it all myself.
The Qjets always seem the best fit for these engines and they run out really well - power and mileage - if kept clean and adjusted. I recommend staying with it and, as others mentioned, correct CFM for engine is important, especially if someone has gone to a later model carb.
Three of these trucks, two of which had aftermarket intakes when I got them (one a 350, one a 383 stroker, and one a 402 BB) came with the Edelbrock version of the Carter AFB. I have found those to be very dependable and a lot easier to clean/rebuild than the Qjet, although correct fuel pump pressure seems more of an issue with these. The 402 BB with the AFB type powered a 72 C30 mororhome and we drove it 85k miles all over the US in 18 years. I never had to open that carb,
Best wishes have fun with it.
NRA Member - Life, Benefactor, Patron
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Campfire Tracker
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quote=northern_dave]Do you have a square bore intake to use? Id put the qj on the shelf and grab a holley quick fuel with electric choke. HR600 or HR650 I don’t have a square bore intake. I was leaning towards the 1406 Edelbrock with the adapter plate The edelbrock is an affordable way to go, pretty simple carbs. Probably a little less to go wrong, less leak prone. [/quote] I'd probably go with the matched Edelbrock carb for that mani. We restored a 69 Chevy C10 Ambulance and use the OE Q-Jet, rebuilt by someone local to us. It started up easily and runs just fine. It however will not be a daily driver.
Fight fire, save lives, laugh in the face of danger.
Stupid always finds a way.
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Campfire 'Bwana
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Campfire 'Bwana
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I attended one of the first QJ rebuilding training sessions GM sponsored in 1966, at the GM traing center in Memphis. The first car to run a QJ was the 65 Chevy 396 big block, and that carb had some growing pains that couldn't be fixed. GM did a recall on all of them. I've probably built up several hundred of them since then. It's one of the best engineered carburetors on the market, with the Carter AFB running a close second. Edelbrock is a third rate clone of a Carter, with a bunch of manufacturing shortcuts used to reduce the cost of manufacture,. If you have a flow bench and several thousdand dollars' worth of tuning parts, go for an Edelbrock.
The trick is getting a QJ that's calibrated for a specific engine, since they were used on everything from a 230 cubic inch Pontiac overhead cam inline six to a 500 cubic inch Cadillac V8. One size definitely does not fit all! There are also 22 consecutive adjustments to make during a rebuild. Don't skip any of them, as many of them have an effect on the next one. The best way to clean any carburetor during a rebuild is to boil the parts in a big stainless steel stock pot, with water and Dawn dishwashing liquid. Then give all the parts a HOT water rinse, and blow massive quantities of compressed air from a needle-point blow gun through all the passages. The boil and rinse softens the deposits- - - -the air blows them clean. Spray can degreaser doesn't do much other than give the mechanic a good buzz. Have fun! I was wondering when someone would get around to mentioning the Carter AFB.
Slaves get what they need. Free men get what they want. Rehabilitation is way overrated. Orwell wasn't wrong. GOA member disappointed NRA member 24HCF SEARCH
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Man I see a complete frame off rebuild right there! What a great project. That's my favorite Chevy body style. You've got a great project. How far are you from Aberdeen, S.D. ? I have some family there that might have some connections for rebuilding the carb. I am about 2 hours from Aberdeen. I'll give Kenny a call and see if he has any sources on the Quadrajets. He won't, he's a Ford guy but he has allot of friends in the hot rod world.
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Holly used to, about 45 years ago, offer a spread bore model as a direct replacement for Quadrajets. I had one and it worked beutifully. It was a 650 cfm as I recall and fuel economy just about doubled on a '70 model 300 hp 350.
Good Luck with your truck!
Rick
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Campfire Outfitter
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Campfire Outfitter
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I attended one of the first QJ rebuilding training sessions GM sponsored in 1966, at the GM traing center in Memphis. The first car to run a QJ was the 65 Chevy 396 big block, and that carb had some growing pains that couldn't be fixed. GM did a recall on all of them. I've probably built up several hundred of them since then. It's one of the best engineered carburetors on the market, with the Carter AFB running a close second. Edelbrock is a third rate clone of a Carter, with a bunch of manufacturing shortcuts used to reduce the cost of manufacture,. If you have a flow bench and several thousdand dollars' worth of tuning parts, go for an Edelbrock.
The trick is getting a QJ that's calibrated for a specific engine, since they were used on everything from a 230 cubic inch Pontiac overhead cam inline six to a 500 cubic inch Cadillac V8. One size definitely does not fit all! There are also 22 consecutive adjustments to make during a rebuild. Don't skip any of them, as many of them have an effect on the next one. The best way to clean any carburetor during a rebuild is to boil the parts in a big stainless steel stock pot, with water and Dawn dishwashing liquid. Then give all the parts a HOT water rinse, and blow massive quantities of compressed air from a needle-point blow gun through all the passages. The boil and rinse softens the deposits- - - -the air blows them clean. Spray can degreaser doesn't do much other than give the mechanic a good buzz. Have fun! I was wondering when someone would get around to mentioning the Carter AFB. I just gave away my calibration box for the afb....it had a pile of rods, jets and springs. I used to love those carbs.
I would not buy something that runs on any kind of primer given the possibility of primer shortages and even regulations. In fact, why not buy a flintlock? Really. Rocks aren't going away anytime soon.
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Joined: Dec 2013
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Campfire 'Bwana
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Campfire 'Bwana
Joined: Dec 2013
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I attended one of the first QJ rebuilding training sessions GM sponsored in 1966, at the GM traing center in Memphis. The first car to run a QJ was the 65 Chevy 396 big block, and that carb had some growing pains that couldn't be fixed. GM did a recall on all of them. I've probably built up several hundred of them since then. It's one of the best engineered carburetors on the market, with the Carter AFB running a close second. Edelbrock is a third rate clone of a Carter, with a bunch of manufacturing shortcuts used to reduce the cost of manufacture,. If you have a flow bench and several thousdand dollars' worth of tuning parts, go for an Edelbrock.
The trick is getting a QJ that's calibrated for a specific engine, since they were used on everything from a 230 cubic inch Pontiac overhead cam inline six to a 500 cubic inch Cadillac V8. One size definitely does not fit all! There are also 22 consecutive adjustments to make during a rebuild. Don't skip any of them, as many of them have an effect on the next one. The best way to clean any carburetor during a rebuild is to boil the parts in a big stainless steel stock pot, with water and Dawn dishwashing liquid. Then give all the parts a HOT water rinse, and blow massive quantities of compressed air from a needle-point blow gun through all the passages. The boil and rinse softens the deposits- - - -the air blows them clean. Spray can degreaser doesn't do much other than give the mechanic a good buzz. Have fun! I was wondering when someone would get around to mentioning the Carter AFB. I just gave away my calibration box for the afb....it had a pile of rods, jets and springs. I used to love those carbs. Had one in my '68 SS 350 Camaro. Ran better with that than a big Holley I had on it for a while.
Slaves get what they need. Free men get what they want. Rehabilitation is way overrated. Orwell wasn't wrong. GOA member disappointed NRA member 24HCF SEARCH
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I have 234k on my original 1981 Quadrajet and 130k on the current rebuild. On a K20 it’ll get as good or better fuel mileage than most trucks in its category on the road today. I vote for rebuild and run it.
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First thing is check the Carb # & date code to see if it's original to the truck (or engine) if it is the calibration will be correct unless someones messed with it.. Then check for excessively worn throttle shaft bores by adjusting the idle speed to factory spec (or your liking)... If you cant get it to idle slow enough with the idle speed screw backed all the way out (throttle blades completely closed) it means too much air is leaking past the shaft bores and they will have to be rebushed... Next check for leaking jet wells by running the engine, Then let it set (without messing with it) overnight... Then (without starting it) get your eyeballs overtop the carb and look down into the primary bores (carefully open the choke plate if necessary)... Now open the throttle several times... You should see fuel squirting out of the accelerator pump discharge holes... If no fuel squirts (or some fuel but mostly air) you have leaking jet wells... You can verify which ones are leaking with soapwater and compressed air after carb disassembly... The fix is to drill or mill the secondary jet well caps out and replace with screw in plugs(with epoxy on the threads)... The primary jet wells (if leaking) can often be carefully restaked... Just putting epoxy over the jet wells never works for long as the heat and fuel loosens it... Your best source for quality rebuild kits, parts & info is Cliffs Q-Jets (Cliff Ruggles) in Ohio... He wrote the best book available on Q- Jets (and iv'e read em all)... I do my own carbs (with Cliffs technical assistance)... But you should expect to pay someone competent about $300 for a basic stock rebuild or as much as $5-600 for a rebushed & jetwelled, recolored & replated, performance tuned works Job... And it's worth every penny... They work fantastic!... Ya'll can keep your Fool injection...
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Originally Posted by Judman
PS, if you think Trump is “good” you’re way stupider than I thought! Haha
Sorry, trump is a no tax payin pile of shiit.
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Only SBC I have runs a QJet. Granted, it’s on a boat, but the thing works great.
Fella I bought it from had it rebuilt at a local carb shop. No clue what he paid.
It’s sat with fuel containing some degree of ethanol in it every winter for the last 8 or 10 years and cranks up and runs smooth every spring. About that time now. 😁
“Life is life and fun is fun, but it's all so quiet when the goldfish die.”
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Campfire Outfitter
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Qjets are good carbs, there are few places that can rebuilt it right still around. You probably need to put bushings in the throttle shaft, it will take some machining skills.
My second choice is Edelbrock AVS, easy to adjust with the new secondary adjustment springs. Holley's are good for HP, but usually take a bunch of work to get right. Edelbrock is quick and easy to tune.
"Life is tough, even tougher if your stupid"
John Wayne
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New Member
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I can see where YOU might think so..... lol
If you want Rube Goldberg check out the "thermoquad" piece of crap that Chrysler used.
Plastic bowl section.
Operated like the game "MOUSETRAP"....
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If ya gotta....send it to that guy in California. He wrote the book.
If he still does it anyway.
Adapting a Edelbrock to a pre 73 Chevy pickup isn't the easiest thing.
Throttle and kickdown cables are funky on them.
Yes, if the trans is Th400, that tv cable.... The TH 400 uses an electric kickdown switch, there is no tv (throttle vavle) cable... The TH 350 uses a kickdown cable (kicks trans into a lower gear for better acceleration) operated by the carb linkage... There is no tv cable on it either... TV (throttle vavle) cables were used on TH700 4r's and TH200 r4's in the 80's to control hydraulic pressure in the transmission...
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OP
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Pretty sure it’s the original carb. It was my grandpas truck that he bought new. I know he replaced the engine. not long before he gave it to me. The original engine was a 350 and that’s what’s in there. Pretty sure it’s a GM crate engine. My dad and him replaced it and my dad doesn’t remember changing anything
Last edited by win7stw; 04/02/22.
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I liked the CarterAFB
The Carter AVS was an odd duck.
I seem to remember some being on the intake crossways.......
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Campfire Regular
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Pretty sure it’s the original carb. It was my grandpas truck that he bought new. I know he replaced the engine. not long before he gave it to me. The original engine was a 350 and that’s what’s in there. Pretty sure it’s a GM crate engine. My dad and him replaced it and my dad doesn’t remember changing anything Call Cliff's Q- jet and give him the carb #, He will know what it is and send you the proper parts kit to rebuild it yourself... Or find someone who can...
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I can see where YOU might think so..... lol
If you want Rube Goldberg check out the "thermoquad" piece of crap that Chrysler used.
Plastic bowl section.
Operated like the game "MOUSETRAP".... Them Thermoquads work great when set up by a good TQ guy... That "plastic" fuel bowl was designed to keep the fuel cooler and prevent vapor lock and also hold more fuel than a Q- Jet bowl... In some ways it was an improved Q-Jet... As a kid the fastest car in town was Bobby L's 69 Coronet R/T 440 magnum 4brl (thermoquad), Torqueflite, 410 "suregrip"... Ran 12's at Union Grove... Nobody messed with it... Not even John A's "Boss 429" or Bill M's "LS-6"...
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Nothing wrong with a good old q jet. Trick is finding somone to get the metering rods set Not me but some old school hot rods are capable
Pontiac went to q jet and phased out the 3 Duce for good reason they were just better and preformed
Holl will probbly be best at the track for maximum power but doubt that’s you intention on a small block c10
Put a Holley on and be prepared for vapor loc
The Edalbrock carb seems to work fine if jus motoring around a stock 350 I have run them on 350 truck most guys hat them say they are junk.
But a lot of those opinions come from guys building max power as there primarily objective.
I would just find a good carb guy and rebuild the stock
Carb it was metered and jetted for that enginge
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