The only reason why the 7.3L was unable to meet the regulations due to the EPA changing the regulations on Diesel trucks. They also changed them again which is why the 6.0L was discontinued and the 6.4L was brought out. Also it is the reasoning for the diesel fuel to be changed from 500ppm of sulfur to 15ppm of sulfur.
Maybe you should do some more research before you open your mouth.
Then you maybe you will actually sound like you know what your talking about.