1970 Quadrajet Date Code for January 1970 BB

[Bob P.]

I just recently purchased a 1970 BB that has a Quadrajet 7040205 EA on it with a date code of 0700. This obviously is the correct carb for the car, but the car build date is Jan 14, 1970, which doesn't match up with the carb manufacture date 0700, which is sometime in March. Since Rochester didn't make this carb in 1969, how would I ever get a correct date carb for this car? Is it possible that it was stamped wrong and should have been 0070? The person I bought the car from was the second owner and according to him this is the carb that he got with the car 30 + years ago. He nor I can't imagine that the original owner would have changed the carb 2 months after they purchased the car. I also can't believe the original owner had it replaced during his ownership 1970 to 1983 with a carb from 1970? So, back to my original question, how would I ever get a correct date coded carb for this car?

[Joe L.]

Re: 1970 Quadrajet Date Code for January 1970 BB

I just recently purchased a 1970 BB that has a Quadrajet 7040205 EA on it with a date code of 0700. This obviously is the correct carb for the car, but the car build date is Jan 14, 1970, which doesn't match up with the carb manufacture date 0700, which is sometime in March. Since Rochester didn't make this carb in 1969, how would I ever get a correct date carb for this car? Is it possible that it was stamped wrong and should have been 0070? The person I bought the car from was the second owner and according to him this is the carb that he got with the car 30 + years ago. He nor I can't imagine that the original owner would have changed the carb 2 months after they purchased the car. I also can't believe the original owner had it replaced during his ownership 1970 to 1983 with a carb from 1970? So, back to my original question, how would I ever get a correct date coded carb for this car?

Bob-----


Who says they didn't manufacture the 7040205 carburetor in 1969? They didn't use this carburetor for 1969 model year vehicles but that doesn't mean they didn't manufacture them in 1969. The 1970 model year for most Chevrolet models, including many this carburetor was also used on, began around September, 1969. So, 7040205 carburetors definitely existed with dates as early as September, 1969 if not prior to that time.

Could the carburetor you have have been mis-dated? Yes, it's possible but I doubt it. It could be that the car "languished" in St. Louis for some reason well after the body build date and, when finally completed, had the carb installed on it. Or, it could be that the car had a very early carburetor failure and the original carb was replaced.

[Bob P.]

Re: 1970 Quadrajet Date Code for January 1970 BB

I understand what your saying, but the decoding book I'm looking at indicates that the 4th digit, the "0" in the part number, indicates the year the carburetor was produced, not the model year it was produced for, so in this case it would have been produced in 1970. Therefore according to the decoding book, that digit would be a "9" if it were produced in 1969?

So, in any case this carburetor is not date code correctly for my car, correct?

If this is not correct, how would this be judged for this car?

[Joe L.]

Re: 1970 Quadrajet Date Code for January 1970 BB

I understand what your saying, but the decoding book I'm looking at indicates that the 4th digit, the "0" in the part number, indicates the year the carburetor was produced, not the model year it was produced for, so in this case it would have been produced in 1970. Therefore according to the decoding book, that digit would be a "9" if it were produced in 1969?

So, in any case this carburetor is not date code correctly for my car, correct?

If this is not correct, how would this be judged for this car?

Bob------


In that case, all 1969-built 1970 model Chevrolets with Q-Jet should have a carburetor #7049205, right? However, no such carburetor ever existed. The fact is that the 4th digit indicates the MODEL YEAR the carburetor was produced for.

Your carburetor would not be considered correctly dated for your car. However, as I described previously, there is an outside chance, however slight, that it is the carburetor that was originally installed on the car. The problem is that you would have to otherwise document this occurred which would be extremely difficult even if it's actually what happened.

[Bob P.]

Re: 1970 Quadrajet Date Code for January 1970 BB

I'll accept your argument. So the date code would be julian day and year of production, correct?

My guess is that the original failed and was replaced under warranty a few months after the car was produced.

I guess I can search for a correct date coded one or take a hit on my points for having an incorrect date. Not sure how it would be judged and how many pints I would loose.

Any idea of where to search for a correct date coded carb?

[Reba W.]

Re: 1970 Quadrajet Date Code for January 1970 BB

If the carburetor is correct in all but the date, it only loses 20% of the available points under the CDCIF matrix. Weigh that against the search for and the cost of a correctly dated item. Maybe a mechanical judge will answer the correctness issue.

You can download judging sheets to look at point assignment at https://www.ncrs.org/membership/scoresheets.html

[Jeffrey S.]

Re: 1970 Quadrajet Date Code for January 1970 BB

I understand what your saying, but the decoding book I'm looking at indicates that the 4th digit, the "0" in the part number, indicates the year the carburetor was produced, not the model year it was produced for, so in this case it would have been produced in 1970. Therefore according to the decoding book, that digit would be a "9" if it were produced in 1969?

So, in any case this carburetor is not date code correctly for my car, correct?

If this is not correct, how would this be judged for this car?

Bob,
The fourth digit of the part number does indicates the year the part was designed for. The third digit (in this case the "4") indicates the decade- "4" indicates the '70's. The fourth digit of the Julian date code indicate the year in which it was actually manufactured. The part number, 7049205, if it exists, would be for a 1979 car or truck.

[Dallas K.]

Re: 1970 Quadrajet Date Code for January 1970 BB

There's a 7040205 EH carb over on the Corvette Forum, dated 2339 in the C3 parts for sale/wanted section. Price is $525 shipped and it is located in South Jersey, New Jersey. Not mine, just saw the add.

[Joe L.]

Re: 1970 Quadrajet Date Code for January 1970 BB

Bob,
The fourth digit of the part number does indicates the year the part was designed for. The third digit (in this case the "4") indicates the decade- "4" indicates the '70's. The fourth digit of the Julian date code indicate the year in which it was actually manufactured. The part number, 7049205, if it exists, would be for a 1979 car or truck.

Jeffrey------


By 1979 Rochester was using 8 digit GM part numbers for carburetors. In fact, that change occurred about 1976. So, 7049205 was never a part number for a carburetor. It was never even a part number for any Rochester component part, at least not for one that was ever released for SERVICE.