1964 Valiant "Get Runnin & Drivin"

I've heard that the frame cracking there was what killed a bunch of those trucks. Though I've never seen one for myself.
The only one I've ever seen was an older (63) town panel wagon that my cousin had, a previous owner had swapped in a400 from a later c body, and what a hack job it was. The whole frame rail flexed when he turned the wheel. I think they crudely retrofitted the steering box from the car that donated the engine