This guy is a little rough, but he knows what he is talking about. I have seen much of what he is showing at car shows. Welding onto one of these frames is never a good idea. Ford made these frames from double layers is .125" pressed steel components. IHC was very little better. On the Ford, the weld that should never be there is only on the outer layer of frame material. IHC frames were flexible and welding on these frames can cause the frame to fail at the welding. In the rural area where I lived, the IHC Dealer used to say, IHC made a strong cab and box to support the frame.
Anyway, watch the video. There is lots of very good information in it. See how many things you can spot that the guy did not mention.
https://youtu.be/Qhr4sMCECuQ