The front did not have shock mounts and the rear did.
The front is mounted on the car without the inner bumper and the rear is tucked in on home made brackets with the shocks removed…
Ok, so just make sure your replacement front bumper is for a '74 that came with non-shock mounted front bumper. Both the standard '73 and the shock mounted '74 front bumpers have their bolt holes in a different patterns than the non-shock mounted '74's.
'74 rear bumpers should all be the same, and may interchange with some of the later years too, not entirely sure though.