The first line, "S2MS-9510-A" represents our O.E. (Ford) number, used for their records/catalog to keep track of which vehicle it would be installed on. While there are resources dedicated to decoding this code, it is unused by Holley when attempting to source a rebuild kit or service part. The second line contains the list number "3259-1". We can use this to look up information like jetting, proper rebuild kit, available replacement parts and more. There are multiple books dedicated to researching Holley carburetors (including Holley's own #36-51-7 Illustrated Manual) but for those seeking a quick resource, check out their Master List found HERE.
The Master List shows that this carburetor is rated at 725 CFM and was initially built with a 68 primary jet and 78 secondary jet along with an 8.5" power valve. Due to the unique nature of this carburetor, there are no off-the-shelf to rebuild kits available. It would be best to speak with one of Holley's Technical Service Representatives at 1-888-258-3835 for their recommendation on what would work best.
Moving on, 0798 is our date code; Holley used a three digit up to 1973, after which they moved to the four digit code you see here. Decoding them is as follows:
- Three Digit - Example 763 > 7 - Year (1967) , 6 - Month (June) , 3 - (Third Week)
- Four Digit - Example 0798 > 079- Day of Year (would land in March) , 8 - 1978/1988/1998/2008
When searching for used carburetors, note that three-digit date codes are pre-1973. Service carburetors (dealer replacements) will also be stamped with a four-digit code similar to post-1973 units, the carburetor shown above was a service unit produced in 1978.
Hopefully this guide shares a little insight onto how Holley carburetors are identified, as always you can contact our Technical Service department at the toll free number above. If you are interested in checking out the local swap meet or garage sale, see below for a list of commonly sought after carburetors for restoration projects.
