Scammer Alert: calebgrandpa56

They were mandated in 74. I have done tons of research. When the model year 1974 started, it was actually a guessing game if you car had them or not. My car has mounting provisions for both non-shock and shock mounted bumpers.
I generally never post in a scammer thread, but I'll respond to the dates and tell you not all '74's had the shock absorber bumpers either. A short time ago I sold a '74 Duster that did NOT have the shock absorber bumper in the front, but did in the back. Factory. It also still had the small bolt pattern and drum brakes all the way around. And you are correct, I've never seen a '73 A-body with the shock absorber mounts (but that don't mean they didn't exist).