Upper A Frame Bushings
I'll bet your working on a 6 cylinder A body car.
Those bushing "collars" were hit or miss when they were installed on the upper control arm assembly line.
For some reason a Chrysler engineer thought that they did some good, for some reason or another.
In the real world of things, they are worthless, and don't do anything.
Press them on if you wan't too, but don't loose any sleep over it, if you don't.
I never put em back on, in any of the UCA's that i have ever rebuilt.
And ya, they only put them on the rear bushings.