[lks dcvn]

Putting the top on is the preferred method to add more integrity to the body - although others have done it without a top.

It may be good to measure and reference the door opening gaps to see how close you are. Attached picture has been around on the forum and provides the measurements on a nearly rust free Blazer from user VTblazer.

The torsion (rocker) boxes are the LAST thing I replace as they are the key piece of the body that prevents the truck from folding in half with the top off (and doors from binding up depending how much rust the truck has).

If they are even remotely solid - I would keep them on as long as possible. They do not need to be removed to replace the body mounts, a-pillar, b-pillar, kick panels, or even inner/outer rocker.

I replaced all of the sheet metal on my truck with the old torsion boxes on and then replaced them last as they had rust holes in them under the cab mounts. Doing it this way enabled me to fix all the structural rust with the torsion (rocker) boxes in place and then weld in new solid metal to assure the repairs I made were all dressed from below and the new metal would hold the shape of the rig with all the correct measurements, alignment in place.

Good luck on your repair journey!