I have seen the 7027211 carbs (rare to find, BTW) with dates as early as Feb 67. Your period may be at that transition period (just a guess) between the old and newer one. I'm sure GM must have depleted inventory before using the newer ones. The differences are the needle and seat design.
Also, the linkage may be different between the 2 models. The earlier one use the larger sleeves at the carb throttle side and the 7027211 doesn't use a sleeve at the car throttle. The after market throttle linkage for the 67 BB doesn't fit the newer 211 carb correctly because the throttle side needs the large sleeves to properly fit. My 67 BB car has the 211 carb and also the 2 piece linkage that came with it when I bought the car over 30 years ago. My 67 LOS car that uses a different carb number all together also uses the 2 piece linkage.
BTW, a LOS car without AIR? I thought that was mandatory in 67 for California.