I’m hesitant to resurrect and old thread like this but I was wondering if there is any new insight on the Rochester C carb ? By reading this thread, I found out that my carb is not stock to my 1941 Chevy pickup. My carb is also the Rochester C and I guess that I will use a “B” kit for the rebuild.
You might check to see if (and how much) the air horn and float bowl are warped while you have it apart. You can see my postings on this of a month or two ago. Good luck with it. As you probably know by now there was no Rochester C carb...only the ones shown in the link Tim provided.