74 bumper shocks

Apparently 74 was the changeover year. The body service manual references the fillers as (if applicable). And the attachment of the bumper " to energy absorber units ( or to bumper supports)". This wording is used for front and rear.
Here's a pic of the absorber guts. I took mine apart to clean up and paint them, but kept as stock. Not sure if you need to drain them to get full compression. Because of the spring, i would think tack welds or screws through both cans may be needed to keep them compressed.