Gentlemen, did a search and a lot of reading about removing those pesky body mounting bolts. The upshot of opinion is that most are rusty and require holes cut in the floor for access. My problem would seem much simpler. I removed the number 4 ( from GM diagram ), skipped 3, as it appear to be a rubber plug, and then put a socket on 2. It turned fairly easily, but then, beyond a certain point, just spun around and didn't come down any further. At this point I reasoned, "You have broken off the caged nut, as have so many better wrenches that have travelled this path before you." So, on a whim, I tried driving it back in, and it cinched up perfectly. Therefore, I reason that it is not broken.....I just can'd get it to drop down. The big washer is rusted to the head of the bolt. I have tried ice tongs, but they didn't work. How can I convince this bolt that it needs to come out? ( Yes, I have tried strong language. )

Wow, I'm not sure I would have figured that out before I cut a hole in the floor.

Smack around the perimeter of the washer with a punch, constantly moving in a circular motion as you hit it. Do about 100 whacks.

where did you get your body bushings and did they come with the hardware.

Wow, I'm not sure I would have figured that out before I cut a hole in the floor.

Smack around the perimeter of the washer with a punch, constantly moving in a circular motion as you hit it. Do about 100 whacks.
A little trick that worked for me .
drilled a 5/16 hole above the cage nut used pb blaster with straw to soak top of the cage nut .waited a few days then unscrewd the bolts with a 1/2 rachet came out like butter.Installed push in plugs in the holes that I drilled.

I don't have replacements yet. I believe NPD sells a kit.
R.B.

I think that all but 1 cage nut broke on me. I cut the holes in the floor and the patched it all up. I like the idea posted by abodybill, this would save alot of time by soaking the nuts with liquid wrench or similar and then tring it the next day. It always amazes me how well liquid wrench or PB blaster works on 30 year old rusted nuts.
good luck,
Tony