This topic got heated last year when a few guys sweared that they had NEVER seen a drum brake 74-76 A body car. I have seen plenty and even owned a few.
The last one was a 73 Dart Sport with a dead slant sick. It had 10" front drums (Finned) and 9 inch rear drums. It had the large ball joint upper control arm. The 9 " front drum cars retained the small ball joint design. ALL the 4 wheel drum A body cars had the small bolt circle.
Stores like Kragen/Advance/O'Rielly and even Rock Auto can have mistakes in their books/computers. I have argued with parts counter guys on several occasions about parts that were on my cars since they were built. Even Ma Mopar screwed up every now and then.