Front Drum brake troubles on a 1964 Dart
Later 9 in drums are finned. I think they started in 70. Heavier and I would think less likely to warp. I put a set on my 64 and they work fine (for 9 in drums anyways). You can also use 67 or newer shoes and adjusters but have to get a matching set, the shoes have the posts for the adjusters where shoes for early cars are identical but missing the studs. The newer style is more reliable.