Carter AFB 3721SB carb

[William F.]

Anyone know if this model AFB (Not sure if the "S" is an S or something else) has any Corvette applications? It's on a 340 hp '62; I know this is not correct carb for this application according to the judging manual.

[Timothy B.]

Re: Carter AFB 3721SB carb

Bill,

I know it's the service replacement carburetor for 63-65 Corvette and probably (not 100%) the 62 model year with AFB carburetor.

[Edward B.]

Re: Carter AFB 3721SB carb

Per CBTN, the Carter AFB 3721SB was used late 1965 model year on the full size, Chevelle and Corvette 327/300 with manual transmissions. The Chevrolet part number was 3851761.

Ed

[William F.]

Re: Carter AFB 3721SB carb

Do you think jetting, etc. on this carb is suitable for functionality on a driver with 340 hp 327?

[Jim D.]

Re: Carter AFB 3721SB carb

What's the date stamped below the 3721SB? It could be an original for a 64-65 or a service replacement carb.

[William F.]

Re: Carter AFB 3721SB carb

Carb has I (or1) MO stamped just before and at same level as model number. Nothing stamped below model number. What does his mean?

[Bob R.]

Re: Carter AFB 3721SB carb

Can't tell from your explanation what the date is post a picture. A 3721 carb should work fine on a 340 horse engine.

[William F.]

Re: Carter AFB 3721SB carb

Those are the only things stamped on the front passenger side of carb base in a line, not one below the other. Will other stampings be found elsewhere on this carb?

[Timothy B.]

Re: Carter AFB 3721SB carb

The only other ID is the aluminum tag if it's still there. They are good carburetors, don't be afraid to use it on your 340hp engine.

[Jim D.]

Re: Carter AFB 3721SB carb

An original Corvette carb would be stamped as shown (this is March 65) and have the aluminum tag as well.

carb..jpgcarb. tag.jpg

[Stuart F.]

Re: Carter AFB 3721SB carb

The 3721sb is a good compromise carb for use on any L-75 or L-76 62 thru 65 Vette engine. The jetting is good, but not ideal. If it runs good with no lean surge or hesitation I'd leave it alone. I run one on my 63 L-76 and leave my 3461s in a boxon the shelf. It is too valuable to leave on the car. My 3721sb is sweetened up a bit both in primary and secondaries, and I lightened the air valve weights to match my 3461s. The main difference for the 62 is the fuel inlet piping as it uses a glass bowel filter on a pipe stub.

Stu Fox

[William F.]

Re: Carter AFB 3721SB carb

Thanks to all