Thanks for telling me where to find the date stamp Ethan!
My focus is & has been on 1970 Pontiac carbs;
Up to yesterday, I have only one (original, not service replacement) 1969 carb, and one service replacement 1968 (RA) carb;
I have seen and looked at 67-68 carbs, but since they are not my focus I haven't taken the time to observe differences and I haven't run a cross any that I felt were below value...