I have a 1970 Cutlass
Can anyone confirm that the rear upper and rear lower control arm bushing are the same part?
I phoned Rock Auto and they show them to be the same Moog Part # K5161

I thought the rear upper had a stop so that the bushing would not go all the way thur the "ear" on the rear end>
Scott

 

Should all be the same thing.
Sleeve, rubber, shell.

 

All the same part number. They have a small shoulder as you described. The end with the flange is bigger than the other end, and the holes in the arms correspond. The step serves as a stop for the ears in the diff. housing.