Holley date Codes

[Ray]

Can anyone explain this date code to me please? I am looking at an item on Ebay described as: OEM 1965-67 FORD SHELBY GT-350 HOLLEY LIST 3259-1 CARBURETOR S2MS-9510-A 3291 with a date code of 3291. The original 3 digit date codes I understand, but when it goes into 4 digits, I am seeing a lot of conflicting information, not least of which is a reference to week 9 of the month. Any clarification appreciated, thanks.

[silverton_ford]

From the 428 Cobra Jet page - https://www.428cobrajet.org/id-carb

"Aftermarket Holley carbs have four-digit date codes that use the first three digits to describe a day in the Julian calendar, with the last digit used to identify the year within a non-specific decade. For example, "1999" could represent the 199th day of 1969, 1979, or 1989"

3291 = 329th day of 1971, 1981 or 1991

[98SVT - was 06GT]

"Aftermarket Holley carbs have four-digit date codes

In other words a repro of the original carb that Holley sold to SA. It's not date code correct for a restoration. So while it is OEM - orig equip mfg it is not OE orig equip.

[Special Ed]

I think the 4 digit date code started in early 70s and the 70s holleys had casting changes or improvements over the 60s holleys. I buy 70s holleys for parts since the accelerator pumps, choke hump, top airhorn side ribs, and rh side choke top boss was beefed up just to name a few changes besides fuel bowl castings and screws etc.

[Bob Gaines]

"Aftermarket Holley carbs have four-digit date codes

In other words a repro of the original carb that Holley sold to SA. It's not date code correct for a restoration. So while it is OEM - orig equip mfg it is not OE orig equip.

I am not trying to quibble with semantics because we are both saying the basic same thing but not a repro in the true sense of the word but a reissue of the original part by the OEM that differs from the assemblyline part because of date and other changes. Holley of course was the MFG of both the early and later 1970's and beyond marked carburetors .

[Special Ed]

Holley is being bought out by allstar performance i was told.

[pbf777]

    I believe it's generally accepted that 1972 and older production will exhibit the "three-digit" coding, while after that point the "four-digit" coding appeared. 

    So this pretty much leaves out "1971" as a possible production date. 

    Scott.

[98SVT - was 06GT]

Holley is being bought out by allstar performance i was told.

I think Isky is the only speed company that wasn't swallowed up by big corporate mergers and buy outs.
Sentinel Capital Partners: A private equity firm that acquired Holley in 2018 and merged it with Driven Performance Brands. When Holley went public via a de-SPAC merger in 2021, Sentinel kept a major controlling stake in the parent company.