I can't find a tag or stamped number on my carburetor, what do I do?

The best option is to take the carburetor apart and compare the gaskets, needle/seat, and accelerator pump to identify a kit. The cup diameter and overall length of the accelerator pump is especially important.

Can't I just identify a kit by the application?

No, we never recommend doing that. Carburetors have been swapped around over the years and multiple carburetors or variations may have been used on the original application to begin with. There is no way to guarantee you are purchasing the correct kit based on year/make/model.

Holley numbers

Holley carburetors are stamped with the Holley LIST number and/or the Motorcraft number. Holley numbers typically look like xxxx-x(A, AS, AAS), the Motorcraft number is in a LNLL-LL format. For example D7JL-P. Holley numbers will say LIST or have an 'R-' prefix. Any numbers with a digit proceeding the 'R' is a casting number, ie, 6R-956.

Motorcraft numbers

These use a LNLL-LL pattern, ie D7JL-PA. Most Motorcraft carburetors were not stamped directly with the number, they used a tag under one of the float bowl screws.

Rochester numbers

Rochester didn't start stamping their carburetors until the late 1960's. All of their carburetors came with a stamped tag under one of the float bowl screws. Later model carburetors do have a stamped number. These numbers are always in a straight line (never circular) and are stamped into the metal surface. Raised numbers are casting marks and will not correlate to rebuild kits or parts. Rochester numbers are most commonly 7 or 8 digits starting with 70... or 17.... Some of the marine carburetors use alternative number systems.

Mercarb numbers

These carbs are frequently mistaken for Rochester 2G carburetors. The ID number for a Mercarb is always stamped into the surface just under the fuel inlet. You may need to remove some of the paint to clearly read the number, be careful not to grind the number itself off.

Zenith numbers

Very early Zenith carburetors used a tag under one of the float bowl screws, this is most commonly seen on the Model 33 series. Most Zenith carburetors are stamped with a number either directly into the top of the float bowl cover, or on a round dime-sized disc with a rivet through the center. The inner number is the one you want, it's 4-5 digits with a letter at the end, ie 12345B. In most cases, carburetor rebuild kit's don't care about the letter, just the number.

Some YF's had the number stamped on the razor back that runs vertical of the carburetor body.