Holley carburetor numbers are usually stamped on the carburetor body and preceded by the word 'LIST', the letter 'R' or the letter 'O' for some late models. Numbers that are preceded by '6R' or other combinations of numbers and the letter 'R' are casting numbers referring to a particular part of the carburetor and cannot be used to identify the carburetor. You can also refer to the Holley model ID chart
This numerical list is © Carburetor Doctor Inc. and is compiled from original Holley paper manuals, catalogs, parts references, advertising literature and OEM vehicle manuafacturer manuals as well as original research on cores and carburetors that we have worked on. Some of these resources are available on The Old Car Manual Project.
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