confused on these brakes

mkingan said
Here is wheel cylinder from car and rear brakes. I ordered the 9" ones but they too small didn't set in shoe groove

View attachment 1716047578

View attachment 1716047579

From my experience the 6 cylinder cars came with 9" brakes, the 8 cylinder with 10". If your rear end has been "fix" by previous owner anything is possible. Your wheel cylinder replacement should look just like the one you removed.