1952 Roadmaster body mounts...

[krinkov58]

Attaching 2 photos of some kind of outrigger under my drivers floor pan...looks like it takes the same rubber mounts as the rear trunk crossbar (square and round), but at one time had something square and metal on top (one still does in the photo). What is the square thing? Photos suck, it's raining and I'm using a flashlight....

['78Electra Limited]

What you seem to be describing is the cage-nut. The square "cage" holds a square, tapped piece of metal from spinning while allowing some side to side movement for alignment of the bolt. I had to remake most of my body mount braces as well as those cage nuts, its doable so don't give up.

[krinkov58]

Okay thanks man...looks like it's much easier to re-install the new body mounts before the new pans go in so it was holding me up. Hey anything's doable depending on blood alcohol content!