[qcmadman]

i came across a holley app being 1966 chevelle 396/impala 427 ?


3885067-ee
list 3246
054 date code


most carbs have a 4 digit code

can anyone fill me in on this 3 digit code

thanks jeff stealy

 

[Don_Lightfoot]

3 digits are common Jeff as my 1969 Holley 4346 has a date code of 924 which represents (9)1969, (2)February, (4)4th week. To be honest I don't know if the 1965 carbs were coded the same as the 1969's. One might think it could be a 1970 carb from the fourth week of May (if you followed the same pattern as 1969?). Hopefully somebody else can be more definitive and perhaps more knowledgeable on the 65's.

 

[qcmadman]

don
i wounder if it was a over the counter replacement

 

[Don_Lightfoot]

don
i wounder if it was a over the counter replacement

Definite possibility Jeff. Seems to me I've seen my 4346 carbs with dates as late as 1973 or 1974.

 

[Vintage Musclecar]

Jeff;

The original 1960's and early 1970's GM Holleys had a 3-digit date code system where the first character represented the year of the decade ("6" for 1966, "7" for 1967, "8" for 1968, "9" for 1969, etc.).

The second character represented the month, numbers 1 through 9 being used for January through September, "0" being used for October, "A" for November, and "B" for December.

The third character reperesented the week of the month, i.e. 1 through 5.

Around 1972 GM adopted the Julian dating system on Holley carbs. The first 3 characters represented the actual day of the year (1 through 366) and the last character represented the year of the decade. As many of the original GM carbs were serviced for several decades after production ceased, on some models it is difficult to tell which decade a 4-character Julian dated unit was actually produced, although that's essentially irrelevant since it's still just a service unit.

The 054 date code on your 3246 would be the 4th week of May 1970.

Hope that helps.

Eric

 

[qcmadman]

eric
thanks for the info! do you think i should still use this carb on the 375 hp l78 66 chevelle restoration even tough its a service replacement does it make a big difference this carb is in mint shape

 

[Vintage Musclecar]

Jeff;

While the carb should function just fine on your engine, it's technically not the "correct" carb for a `66 L78 Chevelle. The correct carb would be a LIST 3613. The 3246 is for a `66 L72 (427/425) installed in a B-body car (Bel Air, Biscayne, Impala).

If you're not concerned with numbers, I'd bolt it down and forget about it.

Eric

 

[Jim_66SS]

my book also list the 3246 as an early chevelle 396/375; but indicates it as unverified.

 

[Vintage Musclecar]

There is a considerable amount of confusing and outright misinfo circulating in regards to carbs, so you have to do your homework. There are numerous issues even in the Holley carburetor "black book" (i.e. master listings).

Just to clarify again:

3246: `66 L72 427/425 full size cars
3247: `66 L72 427/425 Corvette only
3613: `66 L78 396/375 Chevelle

Eric