Rochester Number decoding

Example: # 7028219
               DG 1938

These numbers can be found on the side of the carb main body next to the throttle lever , 1965 to early 1968 was a round disc 1968 and later ones where stamped into the body on quadrajets


If the date code under the number is 4 numbers "1938" like above it was produced by Rochester
If it looks like "A8 o MM" then it was produced by Carter ,Carter produced millions of quadrajets with original numbers under license from GM. Carter also
produced carburetors with O.E. calibrations with the Carter numbering system, which is 4 numbers followed by the letter S on the quadrajets

7028219

Prefix code. "70" will appear on all late '60's Rochester Carburetors.
      76 and later will start with "170"
      2 - Decade produced.
          702 - 1960's
          703 - 1060's with A.I.R.
          704 - 1970-1975
          1705 - 1976-1979 
          1708 - 1980's 

7028219

Year produced.
     8 = 1968
If the number was 7045219 then
     5 = 1975
7028219 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) Fed
7028219   - Division.
     0, 1, and 2 all indicate Chevrolet.
     4 - Buick
     5 - Olds
     6,7 - Pontiac
7028219  - Transmission most cases
     Even numbers - Automatic Transmission
     Odd numbers - Manual Transmission
DG Production Code.
1938   Rochester produced carburetor Date Code
     193 = 193 rd Day of the year
1938    8 = Year 1968
Other
A8 o MM Carter Produced carburetor Date Codes
A= Jan
B= Feb
C= March
etc....
A8 o MM  8 = year 1968
MM Production Code.
   
This is provided as a general reference only please verify from other sources