I have really rusted floor in my car, how do I know if the rust is critical. Are there any critical spots to look for?
Frame rails. The basic frame system for these cars starts with the front rails which extend back to the rear of the transmission (blue arrows). Then the torque boxes, (yellow arrows), carry the structure to the rocker panels, (pink arrows), which tie into the rear torque boxes, (yellow again), and finally to the rear frame rails (orange). Take a good look at the shock mounts and spring mounts (white). I have seen cars rust here and nowhere else. Major rust in any of this frame system is something to consider in whether you restore a car or junk it. Everything else is just sheet metal.
