I have the body of my Chevelle lifted and I placed 4x4's between the body and frame. I welded in new front and middle floor braces. I still need to replace the floor pans. Can I do this as the body sits on the 4x4's? Do I have to bolt it back down to the frame first? or can I weld in any braces elsewhere. I'm trying to avoid having to lower the body, then raise it again to finish any painting/detailing/ect.

Turn on that welder and start welding

I am doing that exact same thing... I have a few posts below. I was told the body has to be on the frame to weld in the floors. I understand this is critical on convertables.

I'm just starting the process now and I am going to raise the body with the old floor in place. Drill out the spot welds and remove the braces marking them so I can replace them exactly where they were. Then replace the braces using the old rusty floor as a guide. Then i'm going to clean and paint the frame the best I can with the body raised 8 inches off the frame.

(I'm also changing the body bushings at the same time)

Once I have the braces replaced, I'm going to lower the body and then cut out and replace the old floor.

I don't know if that's right, but that seems to be what i've been told.

I did new floors on my convertable. :cool:
I did not lift the body untill the floors and all the welding was in done. The supports were also replaced and re welded to the rockers and the floor I installed the frame bolts seatbelt bolts then started welding. Before any cutting was done I made brackets to hold the firewall to the back back seat bracket this was done on both sides. I also used speed screws to hold everything together before the first weld was done. Later you can remove the speed screws and weld up the holes if you position the screws just right it looks like the factory spot welds. " Dont forget the supports"