Stefonius wrote:
F350/450 with bed will bend. An F450 chassis cab frame will not.
Keep in mind that you can install a pickup bed on a F450 chassis. People here have done it. As far as the frame being exactly the same goes, wouldn't it mean that a F350 frame would be just as strong as a F450 chassis?
Finally, I just speculated they could be different considering the weight difference. If you have links that give the details, I'd like to see them. I was unsuccessful other than one post in another forum that suggested the curve of the frame rail is different in a F350 vs F450.