What are you planning on changing? If you're going after the trunk floor panels, you should measure out the distances down on the bottom where the gas tank sits as well. It looks bad when people have to redrill all of those holes because the gas tank doesn't fit. Also, you will want a straight, origninal gas tank to help fit the new panels (empty, flushed out, and covered of course). It also looks like you have enough solid material there to go after the panels one at a time. Leave as much original for as long as you can.
I am going to replace the trunk floors. I also will need to replace/repair both rear frame rails (rusted just around the shackle mounts). I don't have a tank yet, guess I should get that before doing any welding. After taking the measurements around the tank lip can I remove one of the floors?
Sounds like you're about ready. The trunk drop offs can be tricky if you are worried about saving the quarters. Don't immediately throw out the originals either because you may need them as a reference depending on the quality of replacement parts you are using. I have a few picks of the process on my website that might help but nothing too detailed.
After checking out your site, it looks like I've got to due alot of the same things/forums/images/icons/frown.gif. My work space is NOT big (1 car garage with lots of crap in it). My lower quarters do need to be replaced. I assume (I hate that word) that I can do that after the trunk floors. Is that correct?