Decode that Rochester Carburetor

1975 and Earlier | 1976 and Later

Example stamped on carburetor:
7028219
DG 1658

70 ~ Prefix code for all late 1960's & 1970-1975 Rochester carburetors
  2 ~ Decade
    2 ~ 1960's
    3 ~ 1960's with A.I.R
    4 ~ 1970 to 1975
8 ~ Year
2 ~ Model
  0 ~ Monojet (1-bbl) Federal Standards
  1 ~ Two jet (2-bbl) Federal Standards
  2 ~ Quadrajet (4-bbl) Federal Standards
  3 ~ Monojet (1-bbl) California Standards
  4 ~ Two jet (2-bbl) California Standards
  5 ~ Quadrajet (4-bbl) California Standards
  6 ~ Varijet (2-bbl) Federal Standards
1 ~ Division
  0, 1, 2 ~ Chevrolet
  4 ~ Buick
  5 ~ Oldsmobile
  6, 7 ~ Pontiac
9 ~ Transmission
  Odd numbers w/manual transmission
  Even numbers w/automatic transmission

DG ~ Broadcast (Customer) Code
1658
165 ~ 165th day of the year beginning with January 1
8 ~ year

Early Carter & Rochester Quadra Jet carburetors will have a circular metal tag affixed to the front, left side. Date code is a letter/number combination where the letter is the month, January through December (A...M omitting the letter "I") and the number is the day of the month.

A - January	B - February	C - March	D - April
E - May	F - June	G - July	H - August
J - September	K - October	L - November	M - December

This example is a Carter built Quadra Jet for a 1967 Chevelle dated E7 for May 1967 with customer code "DG".

This example is a Rochester built Quadra Jet for a 1967 Chevelle dated J6 for September 1966 with customer code "ES".

704 ~ 1970-1975
0 ~ 1970
2 ~ Quadrajet (4-bbl) Federal Standards
0 ~ Division (Chevrolet)
4 ~ Automatic Transmission
FF ~ Customer code
078 ~ March 19
0 ~ 1970

Note: Broadcast (or Customer) Code is shown on build sheet, block 18, and are not necessarily plant specific. For example the code "FF" has been seen on both Atlanta, Kansas City, and Van Nuys build sheets; Baltimore will show FF-BH.

704 ~ 1970-1975
0 ~ 1970
2 ~ Quadrajet (4-bbl) Federal Standards
0 ~ Division (Chevrolet)
5 ~ Manual Transmission
FF ~ Customer code
026 ~ January 26
0 ~ 1970

Note: Broadcast (or Customer) Code is shown on build sheet, block 18, and are not necessarily plant specific. For example the code "EH" has been seen on Atlanta, Kansas City, and Van Nuys build sheets; Baltimore build sheets will show EH-BH.

1976 and Later

Example:

17080219
2339 CNO

170 ~ Prefix code for all 1976 and later Rochester carburetors
8 ~ Decade
  5 ~ 1976 to 1979
  8 ~ 1980's
0 ~ year
2 ~ Model
  0 ~ Monojet (1-bbl) Federal Standards
  1 ~ Two jet (2-bbl) Federal Standards
  2 ~ Quadrajet (4-bbl) Federal Standards
  3 ~ Monojet (1-bbl) California Standards
  4 ~ Two jet (2-bbl) California Standards
  5 ~ Quadrajet (4-bbl) California Standards
  6 ~ Varijet (2-bbl) Federal Standards
1 ~ Division
  0, 1, 2 ~ Chevrolet
  4 ~ Buick
  5 ~ Oldsmobile
  6, 7 ~ Pontiac
9 ~ Transmission
  Odd numbers w/manual transmission
  Even numbers w/automatic transmission

CNO ~ Broadcast (Customer) Code
233 ~ 233rd day of the year beginning with January 1
9 ~ Year