Technical What carb do I have?

Got a 4bl Carter Quadrajet ("mfg for GMC") on a cast intake. OLD and NASTY! The numbers I can read are - "D36 (R) (C) 70A7687" maybe(lol) on the main body, "47876" on the front linkage and "44889" on the back. ...and is it worth rebuilding?

 

picture didn't come through...

 

also if you look at that A in the number, is it really the number 4?

 

squirrel, you are correct, sir, it is a '4'. Eyes must be the second thing to go!

 

does it have any numbers like this?



I think the number you provided is a casting number, not a stamped carb ID number.

 

I can't find any numbers over 5 or 6 digits that might be an ID. Maybe Carter had some other way to ID? In your pic it looks like the ID is to the right of the "Quadrajet" stamp? my carb is flat to the right of that stamp and it's where the "Carter mfg for GMC" appears. The other numbers I found are on the throttle linkage itself (41254) and on the underside of the butterflies - 48158 between the small 'flies on the body itself and 29909 on the lg flies themselves. Dang!

 

might be an early one that had a tag under an air horn screw.

anyways, it's likely a 1960s Qjet from a Chevy, it might or might not work after a rebuilt. They're getting harder to find, although they also are not in high demand.

 

I get the feeling I should just consider getting a different carb, squirrel. Recommendations for just a plain old vanilla street version carb for a stock 350?

 

If you can post some pictures of it, maybe we could tell if it's worth messing with...I have one vehicle right now with a stock 350 in it, and a Qjet, and it works just fine.

 

It'll be a day or two, I don't have a smart phone so I'll need one of my son-in-laws to maneuver a pic to me so I can post it. Thanks for the input, squirrel. Can you check on this thread over the next few days so you can know when I post it?

 

sure

 

Here ya go, squirrel.

 

I hope I'm wrong but I doubt you will ever get it to run right. Those Carters had 5 (countem) circuits for the various throttle positions and most are clogged up. A new Holley 500 CFM four bbl. will make your sbc run sweet IMHO.

 

looks like an mid 70s chevy carb, from what I can see. I'd look a little closer to see if it has a number stamped on it...maybe rub some sandpaper on the pad where the numbers should be? I have one that looks just like that, 17058213 number showed up after I did a little sanding. 1978 chevy truck carb.

 

If you already own it or can get it dirt cheap it's worth it as a parts carb if nothing else, I would still go with a quadrajet for a stock street 350 over any other carb.

 

I'll see if some sandpaper will reveal anything. Thanks guys.

 

Eureka! The application of some 'magic' sandpaper at the right spot reveals ..... wait for it ....
7045213 and D6 and YA !Thanks for the tip! Now, what does that tell you/me/us?

 

I was able to see that it is most likely from a 75 3/4 ton PU w/350ci and 750 cfm . Question is it worth having rebuilt, what should be the most I should fork out for the rebuild or should I go with a later model 4 bbl and what would be the recommendations? Man, it's nice to have you guys for a reliable resource! Thanks.

 

Best carb going for drivability , try it

 

First thing on a Qjet rebuild is to check the slop in the throttle shafts if it is loose then you need a rebuilder that can install bushing to fix that.
Guess I never seen a Carter Q jet or never looked that close are they different than a Rochster

 

Saltflats, I'm not the one to ask. Strictly a carb/engine newbie. Seems like I should try to get it rebuilt, tho'.

 

Here's a video I found that's not easy to watch but I think does a pretty good job of deciphering Qjet carb assembly numbers.

 

If you're thinking of circuits like choke circuit, float circuit, idle circuit, low speed circuit, main circuit, power circuit and accelerator pump circuit, then all carburetors are going to have most, if not all, of these circuits. An exception might be an "off-road use only" carb that didn't have a choke circuit.

 

Those CARTER Qjets were made under contract , at times when Rochester couldn't keep up with GM production. Functionally they are identical to a Rochester.
Quadrajet haven't been used since 1990, and even then they were the electronic jet version, yours is about as late model as a standard type ( non electroniic) Q jet can be.
Qjets are great carbs, much maligned by Holley enthusiasts, but far better at actually metering fuel. You have to spend heaps of money and time to get the same driveability from a Holley carb.
YOU CAN fix this carb yourself.
Take your time and take lots of pictures at each step of dis assembly...there is a great reason to go get that smart phone you always wanted.
Strip it clean it and check for throttle shaft wear. You can bush the shaft yourself ( several companies sell a bushing kit including tools, e.g. http://quadrajetparts.com/) ...or once you have it stripped and cleaned , take the base plate into a rebuilder and have it done.
Buy a quality kit ( Walker) and reasssemble and adjust following the instructions in the kit.
Even though you say you are a newbie, just do it , this will give you a great sense of achievement and years of driving pleasure.
Take your time, use close fitting correct sized screwdrivers so you don't damage the jets and screws. Be extra careful when taking the big fuel inlet fitting off the carb, it has a very fine thread and is easy to cross thread and or strip...

 

97 just gave you excellent advice get you a laptop and go to utube when they are adjusted right nothing performs on a stock 350 as well as aq-jet

 

The beauty of the Qjet is that you can rebuild it yourself, and it'll probably work pretty good. Sometimes there are problems that can't be fixed easily, such as being too badly warped from the bolts being over tightened...but I'd say at least 2 out of 3, or 3 out of 4, are good useable carbs.

Get some good disassembly instructions before you start....there are some tricks, like pushing in the accelerator pump lever pivot pin almost all the way to remove the lever, removing the metering rods first, etc. that make things go more smoothly.

 

That is a plain old vanilla street version carb. I would take it apart and clean it up if it were mine, it doesn't cost that much to find out if its good or not.

If I were to replace it on that intake I would either go back with another or find a carter AFB, I am not sure that the AFB will be a bolt on but they are a good carb and worth the effort.

We used to think that they were the same company. I am not entirely sure that they were not by the time the Q jet hit the market. It should be basically the same carb.