Barely any Brakes

I understand the point about drums not being that bad. I have had several cars with drums all the way around and when properly maintained, they do stop your car.

But here is the problem........

Just about every other car on the road will have a shorter stopping distance than an old 4 wheel drum A-body.

And you can't control the other guy.

The cost of a disc conversion is about that of an intake and cam swap if you do a 73+ disc swap.