Rear drum brakes

‘74 wouldn’t have 9” drums. As a 318 car it would be front disk so it would also be BBP front and rear.

While the A-bodies were never supposed to come with 11” drums from the factory, this isn’t the first time I’ve heard this. I’ll see if I can find the thread but supposedly there may have been a shortage at one point and some cars may have gotten 11” drums to keep the line rolling. With Ma mopar I’d never say never. It’s also been a long time since 1974 so just because it has them now doesn’t mean they’re factory.

What’s the deal with the “lip” on the drum? If it’s a 5x4.5” bolt pattern mopar axle then any BBP drum should fit with the matching backing plates, 10”, 11”, shouldn’t matter. I put 11x2.5” brakes on all my cars.