Today I spent a couple hours repairing the last 4 body mounts. I would have put the body on the frame, but needed a few more hands.
As you can see, the whole stock square nuts and cages didn't hold up so great.
I didn't get many good pictures of the front two mounts, but it basically went like this. Cut and bent an access hole, then cleaned out the old nut and cages, placed my new hardware in, and welded it up.
In the back, I ended up removing the tailgate because it had some rust issues. Then I cut two access holes right near the hinge access. Cleaned up the inside, and mounted my new hardware. I'll weld it back up once the body is on the frame.
Only thing I have left to do is drill holes for the body mount in the rear crossmember. I probably should have just replaced it with one from BJ's, but I repaired it and now have to figure out where to drill my two holes.