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So you're walking around the local swap meet or garage sale and observe a pile of old Holley carburetors, how do you know which ones are basket cases or precious relics for that muscle car restorer? Hopefully, this guide will direct you in the right direction and offer you some insight on how to identify an older carburetor and locate potential service parts.
***CLICK HERE TO SEE LIST NUMBER LOCATIONS BASED ON MODEL/SERIES***
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:
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.
Holley offers a ton of great technical information on the support section of their website! Whether you're looking for exploded views, tuning tips, rebuild information or more, check out Holley's in-depth Carburetor Repository.
For a visual guide on locating your list number as well as help identifying other brands/models, check out this video!
Holley offers a selection of replacement muscle car carburetors, perfect for completing that six-pack setup or replacing a damaged unit. Check them out!
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