7040205 Q-jet question
Thread Starter
Instructor
Joined: Jul 2005
Posts: 231
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From: Hinckley, Ohio
7040205 Q-jet question
I’m looking for a 7040205 quadrajet that is date coded for my car (early July build date), and if I'm paying good money I want an original carb (i.e., not a restamp). Searching around, I found a few on the bag and in one of the auctions someone contacted the seller and made the following statement.
"Its mostly correct right down to the depth of the stamp and the idle backoff but one thing cant be over looked. Its missing the vacuume fitting on the front right side. This connected to the Spark Control System. Its a dead give away. Im sorry to tell you that it is a restamp."
Auction link
Here is a link to a carb that has the port.
carb with port
I then ask someone else who is selling a supposedly original 7040205 about the lack of a vacuum port as described above. This guy tells me that original 7040205’s did not have this port.
So the question is, which is it? Should a 7040205 have this vacuum port? Also, are there easy ways to determine if a carb is a restamp?
"Its mostly correct right down to the depth of the stamp and the idle backoff but one thing cant be over looked. Its missing the vacuume fitting on the front right side. This connected to the Spark Control System. Its a dead give away. Im sorry to tell you that it is a restamp."
Auction link
Here is a link to a carb that has the port.
carb with port
I then ask someone else who is selling a supposedly original 7040205 about the lack of a vacuum port as described above. This guy tells me that original 7040205’s did not have this port.
So the question is, which is it? Should a 7040205 have this vacuum port? Also, are there easy ways to determine if a carb is a restamp?
Melting Slicks
Joined: Apr 2006
Posts: 2,084
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From: Airdrie Alberta
Melting Slicks
Joined: Apr 2007
Posts: 3,189
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From: Tolland CT
If you need a picture, follow this thread down to the posting from Spinadog. A photo of the right side of his carb. Bottom right side of the photo shows a tube which is capped off. Probably the tube you are asking about.
http://forums.corvetteforum.com/c3-g...-70-454-a.html
http://forums.corvetteforum.com/c3-g...-70-454-a.html
Thread Starter
Instructor
Joined: Jul 2005
Posts: 231
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From: Hinckley, Ohio
Thanks! I should of thought about asking for a pic of an original carb. Unfortunately, none of those pics show the port I'm referring to.
Looking at the front face of the carb, the port would be on the right side of the front face. If you click on "supersize" for the first pic in the teamchevelle link in my original post, you can clearly see the port. If anyone could post a pic of a 7040205 that is orignal to their car, I would appreciate it!
Looking at the front face of the carb, the port would be on the right side of the front face. If you click on "supersize" for the first pic in the teamchevelle link in my original post, you can clearly see the port. If anyone could post a pic of a 7040205 that is orignal to their car, I would appreciate it!
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Verdad Gallardo
Pro
Joined: Feb 2008
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From: C3 Forum, Colorado
I'll admit I'm not expert but I do know there are a lot of people out there that claim to be and those people usually don't have a clue what they're talking about. If you go back to the auction site again some posted another reply correcting the previous one. I don't think original 205's are suppose to have that port. As far as I know the only carburetors that should have that port are the one that came factory with California emissions. And if it did it would be a number other than 7040205. It would read something like 7040???
Drifting
Joined: Jul 2006
Posts: 1,259
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From: Deplorableville Nebraska
I'll admit I'm not expert but I do know there are a lot of people out there that claim to be and those people usually don't have a clue what they're talking about. If you go back to the auction site again some posted another reply correcting the previous one. I don't think original 205's are suppose to have that port. As far as I know the only carburetors that should have that port are the one that came factory with California emissions. And if it did it would be a number other than 7040205. It would read something like 7040???
If you have access to the 1970 chassis overhaul manual I believe you'll find your answer. The port you are referring is called the canister purge signal tube (RPO NA9). This is also known as California emissions. You can find the exact reference on page #6M-26, figure Q1. Also in the specifications pages (page 18) you will find the carb part #'s for all 1970 cars and trucks. Without NA9 option, the carb should be 7040205, and with NA9 it would be 7040505.
I will admit I don't have a lot of personal experience with the BB carbs, but this dovetails exactly the way the L46 (350/350) small block cars are equipped.
If you do another search on ebay for 7040205 and completed listings, you will find several other carbs to reference.
Good luck.............
