[alanwoodieman]

this was Ford's error, from 42 up, same cab, they did not lead this seam apparently the cab flexes at this point. on my 41 3/4 ton I welded the cab joint and then finished just like any other welding repair-grind, a little bondo, etc. It has been done for 5 years and over 5000 miles and still looks good. remember even 1/2 ton truck were used like trucks, overloaded and driven on rough roads. look where the rear of the cab mounts to the frame, they are prone to cracks there and look for cracks on the floor above where the floor cover goes on.