The old fords from the late 70s are actually quite good for jumping. They have the longest (and equal sized) twin I beam axles, similar strength frame as modern trucks, and are not nearly as heavy so are not very vulnerable to their own weight. When they were more popular, they were a vehicle of choice for the baja races because only a minimum od modding was needed to make it into a long travel suspension.
I doubt that poor old ford in the video has tracked strait in years though even before the jump.