Only difference I can see is the reinforcement washer on the sway tab. Even the pivots look the same...am i missing anything?
Talking about A-Bodies btw.

Are you talking about A-bodies?

yes sir

Well, 64 wouldn't have a sway bar.
To my knowledge, sway bars on the a bodys started in 1965.
All lower control arms with the sway bar mount tabs on them are all the same from 1965 to 1972.
Then the location changed for the 1973 to 1976 cars.

Are the control arm pivots the same as well?

My experience is that the 63-76 Lower control arms will physically FIT in any of the cars. There were slight design differences, but the specs are the same regarding the attachment points, lower ball joint taper, lower bushing, Sway bar mounting... etc.

thanks all