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Virtual Wrench, Classic car expert
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Experience:  35 years experience Foreign and Domestic
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Chevrolet corvette I have a 1973 Covette with a 350 and auto

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I have a 1973 Covette with a 350 and auto trans. It has an Eldebrock carburetor on it now.. I just found the original Rochester Quadrajet #7043202 for it. I want to install this carb but I have no idea where all and what hoses goes to where on this carb.. So I need a diagram showing which ports goes to where. Also, This carb is setup for a divorced choke and the Eldebrock has an electric choke. They might have changed the intake manifold for there is no place for the divorced choke to hook up to. What should I do there? Can I put an electric choke on this Qjet carb and if so, where, what kind should I get one. Unless I can install on the manifold a setup for the divorced choke. I hope you can help and show me pictures and diagrams of all I need to know about the lines. Thank, Jim Halpin

Hello Jim,


Lets see what you have here. First i read your other question you posted awhile back and i believe you stated that the emissions "stuff" has all been removed correct?





Customer: replied 6 years ago.

Yes, no emissions stuff. Just now with an Eldebrock carb and the Gm intake manifold with no divorce choke set up.




stock intake?

Customer: replied 6 years ago.

Thank You,


If it has the OE manifold, there should be an area on the passenger side of intake next to middle of carb where the choke coil spring (thermostat type bi metal spring) mounts to, and it gets it heat source through a passage in the intake that leads to an exhaust port. As the engine gets warm the heat from the exhaust passes thru to the "choke stove" where the bi metal spring reacts with heat and operates the choke plate on the carb. This was the first design change when they went away from a manual choke, then progressed to an electric choke BECAUSE they had problems with the heat passage plugging up and not allowing heat to the choke stove. The passage gets restricted and reduces flow and may or may not need to be cleaned in order to get the choke to function correctly. Take a look at this site by clicking here and you will see the parts you will need.


In the mean time i will get you some info on the vac lines connections you will need for the Q Jet.






On the Edlebrock carb that is on it now,,,i assume it has a vac hose at the rear for the brake booster, and it should have one for the PCV valve,,,,let me know how many others are connected,,,

Customer: replied 6 years ago.
Will be waiting for the diagrams. How about going to an electric choke since the Eldebrock had one? There are 5 nipples on my qjet and one of them is a "T".
Customer: replied 6 years ago.

Looking at the carb right now:

1. Backside.....only one for the power brake


2. Throttle side.......none


3. Front...fuel inlet side...... one in the lower right hand side .... Top left hand is a "T"

.....below fuel but bigger (1/4- 3/8 size) ....left bottom but on the corner there is one.


4. Choke side on this dome shape valve and there is another going thru a slot that is connected to the dome shape valve.



That's it




You might be able to find an elec choke setup that goes in place of the choke stove. The diagram below is what they look like. The diagram is of one for a different car, but they are very similar.


As for the vac lines, does this have the OE point style distributor or has it been changed to an HEI with a vac advance on it.


The diagrams i have will only show all the lines used for all the emissions devices, and you won't be needing them so i will have to tell you separately which ports will need to be connected and which ones you can cap off.



Oops,,looks like we posted at same time,,,be right back..



The larger port on the lower side goes to the PCV valve.


The T goes to an air cleaner, you can cap it off.


Left bottom goes to vac advance.


The ones on the choke pulloff diapram sound right.



Did i get everything

Customer: replied 6 years ago.

ok bottom left corner on fuel view goes to that dome thing on choke side....right?

the one coming out of slot of choke side (PVC valve?.) you had no answer. Cap of the top nipples over fuel inlet..

The bigger one under fuel inlet goes to Pvc valve.....don;t have one.

Bottom left on fuel inlet side ?????

confused because you did go by the numbers as I listed them


Thanks Jim,,


Does this look like the carb you have?


What kind of air cleaner is used. OE?


Also does it have the OE distributor with the points, OR has it been replaced with an HEI dist?



Let me know and i will label the ports for you.






Hello Jim,


I noticed you have viewed my last post. If you have further questions feel free to reply. If not, please click on accept so i receive credit for my time spent with you.


When i was searching for some pics of the carb for you, i came across the corvette forum that you posted to on the 14th about this and noticed that you didn't receive near as much info as i have provided and that is probably why you came here to ask. So,,,if you need to know where those ports are connected to, just let me know the answers to my last questions so i can label those ports for you....


Thanks for asking!

Customer: replied 6 years ago.
That is the picture of my carb. I do not av a pvc valve.. I have the round and triangle air cleaner from Eldebrock. I do not have the stock air cleaner, tho I wish I did and with any advice from you.....should I or stay with what I have. Best deal for that type of original air cleaner......junk yard? From what car? It has been replaced with the HEI distributor. I would like them all labeled so I know what to do with all of the nipples and to where and which to cap off. What is the best way to clean up this carb? I have the complete rebuild kit. Is it hard? Will this carb be better than the Eldebrock (standard) not modified. Yes I was at my wit end with the forum trying to get answers and you are really helping me out. Do I need this PVC valve? Should I go to electric choke or do the heat stack idea you gave me. Can I use the electric choke from the Eldebrock. ( you nevered answer that ?) Jim

Thanks Jim,


Give me a bit and i will label those ports/nipples for you and answer all those questions and list them all in order so i don't forget anything. I have to run out just for a bit, but will be back soon :-)


Thanks again for getting back to me....



First, it needs to have a PCV valve either coming from the carb, or at the back of the intake manifold vacuum port to one of the valve covers so crankcase pressure doesn't build up and create oil leaks for one.(and there are other reasons) If you don't want to run one from the carb and use the intake vac port, then just cap of the port on the carb.


I wouldn't even worry about getting the original air cleaner assembly unless you can find a used one somewhere, but it will be just fine without it.


The carb will be difficult to rebuild if you have never done one before and you would need to get a large can of carb cleaner to dunk all non rubber parts, and some air pressure to blow out all the very small passages. You might want to have it professionally rebuilt, as that would by far be the best route.


Will that carb be better than the Edlebrock? Yes, if it is rebuilt professionally.


The choke from the Edlebrock will not work on the Q-Jet. You will have to go with the choke stove that i mentioned earlier, or MAYBE find an electric one that you could bolt to the intake manifold and run the linkage to the carb. You can not bolt any kind of elec choke to that particular Q-Jet.


Below is the diagram of the carb with the ports labeled for you.




If you still have further questions just reply, if not please don't forget to click on accept so i receive credit for helping you.


Thanks for asking!





Customer: replied 6 years ago.

About the PVC valve, where do I put the thing and attach it how? Understand what it does but I don't know where to put it. Does it stand in line by itself?


Good morning Jim,


The PCV valve connects into one of the valve covers, It is real important to have one to vent the crankcase system. In the old days first they didn't have them and hydrocarbons would build up in the crankcase system and if the engine backfired, it would literally blow the oil pan up. Then they went with a "down tube" that vented to the road, then they decided you might as well re burn those fumes and save on pollution and even pick up a bit of MPG.....below is a pic of a couple. One of the holes is for a PCV and the other is for a breather cap, which you don't really need, but does help, and looks nice :-)







I have enjoyed working with you and if you ever have questions again just address your question to me and i will answer right away.


Please remember to click on accept so i receive credit for assisting you. and please leave some feedback.

Virtual Wrench and other Classic Car Specialists are ready to help you
Customer: replied 6 years ago.

As soon as I find a picture from the forums that a guys sent me I want to send it to you so you could tell me what it is and if I need it. I don't have a hole in my covers for a PVC valve and I don't know what to do about that. They are real nice highly polished chrome ones and I really do not want to get rid of them. Maybe I can drill a hole??? what do you think?

Anyway, I'm going to push the accept button.. You have been very patient and extrmely professional with my lack of knowledge. Thank you very much. I have already begun to rebuild the carb, taking my time, following the book I have and doing it right.

I highly recommend Virtual Wrench to all of those who needs answers. He is very PROMPT, courteous, and knowledgeable. Wish more mechanics were like him. Thank You , again

Thanks for the accept, bonus,nice feedback and the kind words Jim.


Once you get that picture just use the little paper clip icon to upload it for me.


You need to do something about getting a PCV valve in there or you will have oil leaks down the road. I have never drilled one out, so don't have much to offer on that one, one thing i do know, is that it would need a baffell plate under the hole or else it will suck oil out and cause it to smoke for one...if you look at a valve cover that has the PCV hole, it will have a separator/baffel plate


If you need ANY help on that carb, (there are some pretty important tips they don't give you in the instructions) just open a new thread and address your question to me in the first line of the question.


Thanks again and good luck with the carb! (make sure to get a new float)

Customer: replied 6 years ago.

I believe that I have been talking to you about putting an electric choke on my Qjet that I just acquired during the winter. You sent me a website for buying a divorced electric choke and I have seemed to have lost all of our past emails with all of our conversations. The emails should be dated within the past month. Do you still have them? Thanks

Jim Halpin

Hi Jim!
If you cklcik on the link below it will take you to the other question. For future referance if you look at the very top right of this page,,,,scroll all the way up, you will see "my questions" click on that and you can see all of your questions.
Thanks for getting back to me.

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