[SCG] Rochester Carburetor code decoding

[Bill Hubbell]

Your pink tab appears to have the following numbers:

 

B

7026024

D?  BJ     (I can't really read what comes after the D)

 

Here is what I know about decoding the tags

 

B= probably a duplicate Modification code (see below)

 

7026024 = Model Number (Carburetor Part number)

*            70 - Prefix code. "70" will appear on all late '60's Rochester
Carburetors.

*            2 - Decade produced. 

o        2 - 1960's

o        3 - 1960's with A.I.R.

o        4 - 1970-1975

o        5 - 1976-1979

o        8 - 1980's

*            6 - Year produced. 26=1966

*            0 - Model 

o        0 - Monojet (1 bbl) Federal standards

o        1 - Two jet (2 bbl) Federal standards

o        2 - Quadrajet (4 bbl) Federal standards

o        3 - Monojet (1 bbl) California standards

o        4 - Two jet (2 bbl) California standards

o        5 - Quadrajet (4 bbl) California standards

*            1 - GM Division

o        0, 1, and 2 all indicate Chevrolet

o        3 Cadillac

o        4 Buick

o        5 Oldsmobile

o        6 Pontiac

*            4 - Transmission

o        Even numbers - Automatic Transmission

o        Odd numbers - Manual Transmission

 

D? - Date code:

*            D - Month (A=Jan, D=April, M=Dec.  I was omitted to avoid
confusion)

*            ? - Year - therefore is probably a 6, for 1966

 

BJ - Probably manufacturing change code  

*            Usually only one letter, with "A" representing the first
modification, "B" the second, etc.  I have seen "BJ" on other tags ('65 and
'66) but I really don't know what it means.

 

Ideally your carburetors should have matching tags.

 

Note that if you look up the application codes for Rochester Carburetors in
various books or other sources you may get somewhat different information.
It appears that Rochester was not perfectly consistent in using the above
coding scheme

 

According to the above information, then, your tag codes for:

1966 monojet Rochester carb for Chevrolet, automatic transmission.

 

More specifically, this part # was used on 1966-67 95/110/140(primary) PG
except A.I.R.

 

The "C12" is just a casting mold number.

 

Bill Hubbell

  _____  

From: eamsquared at comcast.net [mailto:eamsquared at comcast.net] 
Sent: Sunday, June 21, 2009 3:43 PM
To: Stock Corvair Group
Cc: Hubbell, Bill
Subject: [SCG] Restoring Choke Pulloff color

 

Bill,

 

Attached is a picture of a 1975 replacement carb on my car.  It is somewhat
yellow but this carb has only 11,000 miles on it.  The attached original
carb pictures show the obvious discoloration you mention.  The original carb
has 104,000 miles on it.

 

Can you shed any light on decoding the "C12" casting number on the
carburetor top and the information on the pink metal tab?

 

Erich Meyer

110PG Monza