Rochester-built quadrajets have a four digit julian-type code signifying actual day & year the carb was manufactured. 0620 is 62nd day of '70 & 2488 is 242nd day of '68. My '68s carb date is on the side of the bottom plate, driver side rear. Carter-built quadrajets had letter & year date codes i.e. D8 for April '68.
An 04C car's (April, 3rd week, 69) carb would probably be in the 1009-1159 range or 100-115th day of 1969.