This may help explain why:
When I opened up the frame rails all I found was rust, the construction makes them prone to collecting water and causes them to flake apart from the inside out.
I will end up with a custom frame under this car, so far I am about 150lbs lighter with the new frame and floor than what I cut out. Also a big advantage for where I am headed.
I should also note that this car, although appearing in great condition when I started, was nowhere near original.