I have my truck chassis/engine/driveline all in control and in working order and have started doing some detail work and fresh paint on everything that looks like it might rust in the next ten years of my driving in Pennsyltucky. That I have a good grasp on but this is my first cab rebuild. I have almost finished doing the floor pan autopsy (much like an alien autopsy because there is nothing in there that is not alien to a 55 chevy). I started with the top layer of patch being 1- Tiger hair fiberglass. Then dug into 2- thick guage aluminum plate screwed to the floor with erector set square nuts and button head flat screws. Then 3- thin aluminum plate riveted to the floor with aluminum 1/16 rivets every two inches. then 4- another layer of thick guage aluminum with steel 1/8 rivets every three or four inches. then I got to 4- some floor pan that was cut from a modern junkyard car that was also screwed to the floor and then welded here and there. After that was layer 5- the actual rusted window screen looking leftovers of my original floor pan that this was all clinching to. Then I found 6- a few patches layered to the outside of the firewall and floor. To end it all out layer 7- was roofing tar that was hardened into a plastic-like crust layer that held all of the water in between all of the patchwork from escaping and therefore rotting things more. Well I have my hands full now. I am currently looking through all of the catalogs to see who has the best deals on these patch parts for cabs and who I can buy the stuff from at carlisle (in my back yard) so I can cheat out shipping charges. Any advise on sourcing these floor and lower cab parts is appreciated. Also, I am looking at things a few steps ahead so I don't screw up what little good I have in the cab which brings me to a few questions from guys who went down this road. How do you get the cab to keep from flexing when doing a new main floor? How do you know when it is squeezing the front to rear lower cab or stretching it apart when doing a new floor? It looks like this floor has been split the whole way across once or twice already anyhow so how do I get it to a factory shape so the door gaps are right? Thanks again guys.