The distributor bodies for any given year were the same for each engine family. The numbers stamped on the side represent the entire finished product. Advance spring rate for the centrifugal advance were different from some models to other models. The vacuum advance came in either dual or single versions, as well as six cylinder or V8. The vacuum advance units could be tuned with a limiting spacer and / or washers inside, along with various different springs.
The good news is that a distributor can be tuned to make it work properly so long as it is made for that engine family. The numbers on the outside will tell someone a different story particularly if they are expecting to find a concours correct part.
A question concerning the multitude of different distributors casting numbers for small blocks in 67. I see they had different numbers depending on 2v/ 4v carbs or what type of transmission. What were the differences in the distributor? The amount of mechanical advance? Were there different type of vacuum advance also? How much performance difference if the distributor was mismatched with different carb or tranny type?
Thanks in advance.