I was reading my 60 Service manual over the weekend, and I saw something interesting in the carb section on AFB rebuilding. There were instructions highlighting the fact that the venturi assemblies were not interchangeable left to right. Not an issue during any of my rebuilds over the years, as I always did one side and then the other, and did not have them both out of the carb at the same time when cleaning them and installing new gaskets, but since the gaskets seem identical, what is the difference between the left and right side assemblies? Are there identifying marks/numbers on them anywhere? Next time I take mine apart, I'd like to double check that they weren't switched side to side during some past rebuild before me, since I didn't acquire my car until 1998, some 38 years after it was originally put together. I'm guessing that the written warning was there because the assemblies could be reversed in their positions and the carbs would still go back together, but would somehow be wrong and not operate as designed?