Correct carb for my 63?

[Frederick W.]

This is the AFB carb stamping for my 63 coupe, 327/300 4spd, May build. I want to know if it is the correct carb.
The latest edition of the JG indicates a 2 character alphanumeric date code, but mine has 3 characters: CC3.



I've searched the board and found others with simliar 3 character codes but many have posted that they have not seen this.

Here are links to a couple of threads where this is discussed:


https://www.forums.ncrs.org/showthre...retor&uid=9445


https://www.forums.ncrs.org/showthre...retor&uid=5418

opinions?

thanks
Fred

[Joe L.]

Re: Correct carb for my 63?

This is the AFB carb stamping for my 63 coupe, 327/300 4spd, May build. I want to know if it is the correct carb.
The latest edition of the JG indicates a 2 character alphanumeric date code, but mine has 3 characters: CC3.



I've searched the board and found others with simliar 3 character codes but many have posted that they have not seen this.

Here are links to a couple of threads where this is discussed:


https://www.forums.ncrs.org/showthre...retor&uid=9445


https://www.forums.ncrs.org/showthre...retor&uid=5418

opinions?

thanks
Fred

Fred------


This is a typical stamping and I'd say this carburetor is correct for your car. I believe the first "C" represents a "change code" and the following "C3" represents March, 1963.

[Mike E.]

Re: Correct carb for my 63?

Fred--
I wrote an article on the 3269S carb (62 AFB) a few years ago in the Restorer--same as for 63. John's right, it is a change code.

[Frederick W.]

Re: Correct carb for my 63?

Ok, good
But that carb is not the one currently bolted to my intake manifold.
This is the carb on the car.
This car, again, was a May build 63.



What do you think?

--Fred

[Stuart F.]

Re: Correct carb for my 63?

You guys should be careful posting pictures of your date coded 63 AFB's. I'm still looking for the one stolen from mine. I have a vivid memory of what it looks like and I check every swap meet closely, as well as postings. I'm 71 now so figure I only have about another 20 or so years to find it, Ha!

What an optimist!

Stu Fox

[Mike E.]

Re: Correct carb for my 63?

That's not too tough-- wrong carb!

[Frederick W.]

Re: Correct carb for my 63?

Ahh, but I've talked to all previous owners and none replaced the carb.
Dated Nov 63.
Could it have been delivered this way?
I bought the 3461 to make correct but first owner believes the car was delivered with the one on the car now

Fred

[Joe L.]

Re: Correct carb for my 63?

Ahh, but I've talked to all previous owners and none replaced the carb.
Dated Nov 63.
Could it have been delivered this way?
I bought the 3461 to make correct but first owner believes the car was delivered with the one on the car now

Fred

Fred------


As far as the PART NUMBER goes, I'd say it's REMOTELY possible that 3721 could have been installed on a 1963. However, if such a carb was installed on this car, it's definitely not the one that's on there now. There is absolutely no way that a car built in May, 1963 could have had an original carb dated December, 1963. That's utterly impossible.

What very likely happened here is that there was some problem with the original carburetor and it was replaced at some time very early in the car's life, probably under warranty. By that time the 3721 had replaced the the original carb for SERVICE.

I just checked it and the original Carter 3461 carb, GM #3826004, was discontinued in July, 1964 and replaced by the Carter 3721, GM #3851761. So, what likely happened here was the original carb had some sort of a problem sometime after July, 1964 and was replaced with the SERVICE carb for the application at that time. It so happened that the SERVICE carb used was dated December, 1963 having been in dealer or GMSPO inventory until that time. Given the manufacture date of the carb, it's very likely that the replacement took place sometime fairly soon after the discontinuation of the original carb. So, I'd say it was likely done in the period of about July, 1964 to about the end of that year. The original owner might have forgotten about it, but I'd say it's a virtual certainty that it happened.

[Stuart F.]

Re: Correct carb for my 63?

It Can Happen! Did to me in 1992. My original 3461 carb was "stolen" by a Corvette repair shop and replaced by a 3720. The car was in their shop for about 2-1/2 months for front end repairs after I hit a deer. While there, I had them also do some mechanical work including the exhaust system, etc.. It took so long to get the car back I even found time to have open heart surgery. When I finally was well enough to work on it again in the spring, it ran poorly and I finally discovered the carb had been exchanged. Well, it was too long after the fact for me to really make a provable claim against the shop, and when I confronted them about it they denied any responsibility for it, of course.

So, I too can tell anyone that I never changed the carb. Leastwise I never intended to.

Stu Fox

[Frederick W.]

Re: Correct carb for my 63?

Fred------


As far as the PART NUMBER goes, I'd say it's REMOTELY possible that 3721 could have been installed on a 1963. However, if such a carb was installed on this car, it's definitely not the one that's on there now. There is absolutely no way that a car built in May, 1963 could have had an original carb dated December, 1963. That's utterly impossible.

What very likely happened here is that there was some problem with the original carburetor and it was replaced at some time very early in the car's life, probably under warranty. By that time the 3721 had replaced the the original carb for SERVICE.

I just checked it and the original Carter 3461 carb, GM #3826004, was discontinued in July, 1964 and replaced by the Carter 3721, GM #3851761. So, what likely happened here was the original carb had some sort of a problem sometime after July, 1964 and was replaced with the SERVICE carb for the application at that time. It so happened that the SERVICE carb used was dated December, 1963 having been in dealer or GMSPO inventory until that time. Given the manufacture date of the carb, it's very likely that the replacement took place sometime fairly soon after the discontinuation of the original carb. So, I'd say it was likely done in the period of about July, 1964 to about the end of that year. The original owner might have forgotten about it, but I'd say it's a virtual certainty that it happened.

Joe,
This was my thinking as well, and is quite likely true, thus the reason I purchased the properly dated and numbered 3461S/CC3 carb.

However, I started thinking about it and the original owner was fairly certain he never had a problem with the carb and never had it replaced. He didn't recall exactly the month he took delivery.

So before I bolted the other carb on I wanted to be sure.

The judging standard states that the car is to be "presented for judging in the condition normally associated with that of a Corvette which has undergone the then-current standard Chevrolet Dealer New Car Praparation for delivery to a purchaser, exclusive of any dealer or purchaser inspired additions, deletions, or changes"

Suppose the carb was defective and replaced late in 63, but prior to delivery to the purchaser. This could explain the original owners lack of memory of it.

BTW, I think the code is November 63 on the 3721S (L3), they apparently didn't use the letter I.

I guess I should just replace the 3721S with the 3461S I already have, but is it remotely possible I could be making a mistake?

Thanks!
Fred

[Stuart F.]

Re: Correct carb for my 63?

Fred;

Ironically, if neither your 3461S or the 3721 (SA or SB) has ever been re-jetted, the 3721 is likely to be the better match for you L-75 engine. The 3721 (in 1964/65) was made for just that application where as the 3461 was a bit "sweeter" to be suitable for both the L-75 and L-76 in 1963. It took me a lot of work exchanging parts between carbs to arrive back at the appropriate jetting in the 3721SB on my L-76, specially with today's gas.

Stu Fox

[Joe L.]

Re: Correct carb for my 63?

Joe,
This was my thinking as well, and is quite likely true, thus the reason I purchased the properly dated and numbered 3461S/CC3 carb.

However, I started thinking about it and the original owner was fairly certain he never had a problem with the carb and never had it replaced. He didn't recall exactly the month he took delivery.

So before I bolted the other carb on I wanted to be sure.

The judging standard states that the car is to be "presented for judging in the condition normally associated with that of a Corvette which has undergone the then-current standard Chevrolet Dealer New Car Praparation for delivery to a purchaser, exclusive of any dealer or purchaser inspired additions, deletions, or changes"

Suppose the carb was defective and replaced late in 63, but prior to delivery to the purchaser. This could explain the original owners lack of memory of it.

BTW, I think the code is November 63 on the 3721S (L3), they apparently didn't use the letter I.

I guess I should just replace the 3721S with the 3461S I already have, but is it remotely possible I could be making a mistake?

Thanks!
Fred

Fred------


First of all, I don't think that the NCRS judging allowance for dealer prep is meant to include things like replacing a carburetor for whatever reason. So, if the carburetor was replaced, whether or not the car was still in dealer inventory at the time, I'm pretty sure that wouldn't make it NCRS-acceptable for judging purposes.

Secondly, when this carburetor was replaced was likely after July, 1964 when the original carb part number was replaced for SERVICE. I seriously doubt that a new 1963 Corvette remained in dealer inventory until after July, 1964. If it did, it was likely just a "demonstrator" or the dealership owner's vehicle. Basically, such a car is then sold as a used vehicle although, since it was never registered, it may be "technically" a new vehicle for DMV purposes. Nevertheless, changes to the car made during the period of the dealership's ownership do not qualify as "originally installed" equipment for judging purposes.

[Frederick W.]

Re: Correct carb for my 63?

Fred;

Ironically, if neither your 3461S or the 3721 (SA or SB) has ever been re-jetted, the 3721 is likely to be the better match for you L-75 engine. The 3721 (in 1964/65) was made for just that application where as the 3461 was a bit "sweeter" to be suitable for both the L-75 and L-76 in 1963. It took me a lot of work exchanging parts between carbs to arrive back at the appropriate jetting in the 3721SB on my L-76, specially with today's gas.

Stu Fox

Thanks Stu
The car does run just great with the 3721SB carb.
I'll probably keep it as is until judging day, then stick the 3461S on there to eliminate any confusion
Fred

[Stuart F.]

Re: Correct carb for my 63?

Fred;

Good plan.

Stu Fox