Well, the cold weather is making its way to the east coast, but with a little shelter, the work goes on..
Still haven't given up faith on this chassis, I have gone over "Racelooks" thread over at Shoptalk, from which I got a few good ideas.
As you can see I started to clean up the tunnel bottom, the cancer seems isolated at the location where the pan head and tunnel meet.
And a closer look, other side is similiar but not as bad
Rest of the front third of bottom of tunnel looks to be pretty solid
As fell as the front half of the pan head..