C2 - '65 300hp AFB Carb decoding

[Brad K.]

Hey, Folks.....I've just obtained a late '65 300hp 4 speed car and I'm confused about the AFB stamping on the base of the carb (I'm fairly new with the midyears so be patient with me!) The numbers are.....C2 3721 SB....

I know the 3721 is correct for 1965 and the SB is the 2nd generation of the design (which is correct also) However the prefix, C2 has me confused. Everywhere I read, it is supposed to be a date code, ie: March of '62

There were no 3721 carbs made in 1962

So my question is.....What do you determine the C2 to mean?

I apologize if the answer is in the archieves.....

[Joe R.]

Re: C2 - '65 300hp AFB Carb decoding

Brad,

Could your carb have been built in 1972????????

JR

[Bill M.]

Re: C2 - '65 300hp AFB Carb decoding

The date code on my 3721 SB is under that stamping, and kinda hard to see (H5).

[Stuart F.]

Re: C2 - '65 300hp AFB Carb decoding

I agree with the other two posters. I have a 3721SB built in 1969 which I bought in 1980. You too probably have a replacement AFB. All the replacements after 1965 were 3721SB models. Look closer for the date under the model number. It is a smaller type and sometimes hard to see. If there isn't one, then you can probably assume the C2 is March 1972. The 3721SB is used as a replacement for the 3460S, 3461S, 3720SA and 3721SA of from 1963 thru 1965 (I'm not certain about the 1962 models).

Stu Fox

[Duke W.]

Re: C2 - '65 300hp AFB Carb decoding

The 3720SB/3721SB were available as replacements for all prior small block AFBs through the seventies, so you probably have a replacement manufactured in 1972 or even '82, but I'm not sure when production ended.

Duke

[Stuart F.]

Re: C2 - '65 300hp AFB Carb decoding

It probably ended when they dumped it on Edelbrock.

Stu Fox

[Brad K.]

Re: C2 - '65 300hp AFB Carb decoding

Thanks Guys for all the good info. I did not know that Carter made 3721 replacement carbs throughout the 70's. Now I need to search for a carb made in the spring-time of '65.....the prefix should read either an A, B, C, or D followed by a "5"......Thanks again! Brad