What we have here is an attempt to buy an internal part for a Rochester, from a professional who wants to do things the correct way. It must be understood that if they just sold bits and pieces knowing that they could be used incorrectly, the customer could then spread the word that their stuff is garbage because it didn't work.
Tags are a problem and most of the carbs that I have seen didn't have them any longer. There are other references on the carbs that can be helpful and some of that information was detailed in a previous post.
One of the interesting details left out of the discussion here is that although the earlier Chev trucks didn't come with Rochesters, GM provided a replacement Rochester carb for them. Thus it is possible to have a truck earlier than 1950 with a correct replacement Rochester carb.
