List 4557 "GG" carb ('70 LS6 M/T)

[VintageMusclecar]

9 = The last digit of the year, in this case 1969
8 = The month of production, in this case, August
4 = The week of the month, in this case, the 4th week.

When decoding the month, remember that 1-9 is for January through September, "0" is October, "A" is November, and "B" is December.

When decoding the year, you have to account for the decade of production as well. A carb with a 3-digit date code is easy to decode, but starting around 1972 they went to a 4 digit Julian date code system which can confuse matters.

The Julian system uses the first 3 digits to denote the day of the year, and the last digit is again the year of prodduction.

Example: 2503
250 = the 250th day of the year
3 = the year of production, which could be 1973, 1983, 1993, etc.

Eric