Bingo. The truck lived in upper NY for a while and now it's been here in RI for the last year and a half.

Surprisingly, there are many sections of the frame that are not bad at all, and some are even rust free. It's strange that such a large crack can develop while other parts are good.
My g/f has just been so discouraged from the rust that she might just start looking for another taco in better shape. The only that would change is she'd trade the 6 cyl for the 4 banger.
I'm afraid that we won't be able to find a welder that would agree to do this job. I'll search around, but there's alot of responsibility welding someone's frame!