11 x 2 Brakes?

11x2's were an early B and C-body brake set up. They didn't come on any A-bodies, and they were replaced by the 11x2.5's around '70 or so.

Also, you can only use 11x2" parts on them. The backing plates are different. The BBP axle offset was the same for all BBP axles, so the backing plates have different offsets for the 11x2, 11x2.5, and 11x3" rear brakes.