'73 Dart Swinger Bumper help needed!!

I've seen several '75-'76 Dart bumpers for the shock absorber style brackets being represented as the '73-'74 versions for the regular bumper brackets. (For some reason, the OP pics are not coming up on my computer.)

* The regular brackets attach to the bumper directly, with or without the reinforcement plate in between.

* The "shock absorber" brackets attach to a VERY heavy, full width reinforcement that is bolted to and pretty much fills the inside/backside of the bumper. They use 4 studs & nuts.

The bumpers do not interchange. I have both, but not sure when I can dig them out for a side-by-side photo comparison.