I am planning on a carburetor rebuild sometime in the near future. With originality as an objective, what is the best carburetor rebuild option. My 1968 327/350 4 speed currently has a “correct” replacement Q-jet carb, model 7044518 dated 1544 (1974 Chevrolet/California/AutoTrans). The matching number carb would be 7028219, dated prior to September 28, 1967 (2717). I am not optimistic about finding a matching number carb, certainly not at a price that I would consider worth the investment.

So would it be better to rebuild the 74 carb that is currently on the car or buy one from a rebuilder that would probably be off of a Buick/Olds/etc., but I might actually find one that has an appropriate date stamp? How would NCRS handle the originality points for the carb numbers, if I chose to have the car judged? Is it all or nothing for matching model/date? Or would less points be deducted if the date stamp matched but model did not?

Also, is there anything functionally different about the California 74 carb as opposed to a non-California model 1968 Q-jet?

 

Try and search for the correct carb. I did for about a month and found it with the correct Julian date. Mine was for a 1968 October 67 build date. I was shocked. I always suspect counterfeit but I can't tell. Maybe a judge could but it looks correct and the seller insured me it was. But still skeptical.

 

If this is for NCRS judging and a judge can't tell the difference, who cares if it's 'counterfeit' or not? It's not illegal to alter the carb numbers (like it would be to change the VIN or possibly the engine block stamp).

 

What did you pay for the carb? Was it already rebuilt or just a rebuildable core that you had to rebuild?

 

Hi ud,
I believe the carburetor line in the 68-72 NCRS Mechanical Judging sheet has 38 originality points, and 22 condition points, for the carburetor, heat insulator, and fasteners.
The carburetor is judged like many other parts; on Configuration, Date, Completeness, Installation, and Finish.
So, a carburetor that was spot on except for the date would lose relatively few points since it does well in 4 of the 5 criteria.
You can go to the NCRS home page and view the judging sheets for your car. You should take a few minutes and check it out!
Regards,
Alan

 

Twinpack, thanks for the info. Also, how did you go about locating the carb? Post in the parts section of this forum or somewhere else?

 

You can try looking here for a correct carb for your car including date......it's where I got mine

http://customrebuiltcarbs.com/index.shtml

 

Hey dog

To add what Alan shared:

The combined points assigned to carb is 60 with the split as Alan stated. Each area for originality is generally assigned 20%, so assuming its rebuilt and condition is 100% you would be looking at a deduction for the date code. I would venture to say you would be looking at a minimum of 20% of 38 or 7 points for a date code that is not consistent with that which is typically found on a 68 carb. There may be an additional deduction for part number and broadcast code. But the guide indicates its the carb, heat insulator and insulator to be judged.

It than becomes a question for you is how much do you wish to invest to earn say an additional 7-10 points...as you've concluded? Your correct carb would be the GM# 7028219 with broadcast code DG. The DG code indicates that this carb was specified for a Corvette 327/350 engine with manual transmission and we know that only 9,440 Corvettes were built with this configuration.

What makes this a "correct" replacement carb?

I would tend to rebuild your 74 carb but continue to search for the "correct" carb for a 327/350 Corvette motor...recognizing as you do that in the end you may not find it.


Yes...engineered to comply with 1974 California emission control regulations which I would venture to say that is was originally tuned to be leaner than your 74. But than it could have already been adjusted for your motor.

 

It cost $225.00 and was rebuilt. Bought from Monzon Carbs.

 

I would tend to rebuild your 74 carb but continue to search for the "correct" carb for a 327/350 Corvette motor...recognizing as you do that in the end you may not find it.

 

This makes the most sense to me. It will either take you some 'time' or big money to find a "correct" carb body. (The body has the numbers stamped into it. You can only swap out the body and keep your other components, if you wish. That is what I would do, anyway.)

Keep the car operational and enjoy it while you are looking for the right parts.

 

Thanks everyone for all the excellent responses! This is exactly what I was hoping to learn about the NCRS judging process, so I can make an informed decision. And thanks also for the suggestions for locating a numbers matching carb!

Hunt, thanks again for the excellent information you provided and the suggested action, which I believe is sound advice!

Very good question about the term "correct" and point well taken. I am still very much a novice when it comes to Corvettes and NCRS, but trying to learn more. When I used the term “correct”, the thought was that it is an “OEM similar model replacement” … a newer Rochester Q-jet as opposed to a Holley, Edelbrock, etc., but that it is not a numbers-matching unit.

I realize now that perhaps it was not “correct” to use the word “correct”, since the replacement may have differences of which I am not aware that would render it “incorrect”.

Is there a generally accepted definition of the word “correct” with regard to auto parts and NCRS? Is the"correct" use of "correct" typically synonymous with "numbers matching"?

 

Commercial rebuilders suck. It would be best to find the carb that matches your engine.

Someone above said the "California carb" would have been tuned lean. How would you even know? It's NOT the correct carb for your engine - and it could be tuned rich, lean, perfect, and who knows what it'll run like on a 327/350. It's a motorhome carburetor.

If you had the original specifications (air bleed sizes, etc) your 1974 carb could be set up to perfectly mirror the original carb - or be set up perfectly.

At any rate - avoid commercial rebuilders at all costs. They really mess stuff up to make a "one-size" carburetor.

 

Service replacement!

Well let me add that your service replacement Rochester Q-jet carb would be a configuration consistent with the original carb configuration therefore it would score full points..or the 20% for configuration. If its rebuilt with correct plated finish...than it would score the full 20%. If all parts are there (completeness)...than you earn the other 20%. These are all points scored on the originality scale.

If for example you did not have it rebuilt with a refresh on the finish...than you would score the 20% for finish assuming its the correct finish now. But than you lose on condition assuming the finish has deteriorated or faded...kind of the way it works.