I just compared the above photo to my 67 barracuda repair manual. The dimensions from the torsion bars forward are exactly the same as well as the 43" in the rear.
I sure don't know. I finally found my (paper) 74 Dodge manual, they do not even mention Demon. They just show "V, L" lines and the drawing does NOT match the one posted above. I'm not familiar enough with body work to know
Some of this may be in difference in methods? as the points are not exactly clear in the drawings. For example, in the posted drawing, the diagonal, 161.74, is listed as 158.89 in the '74 book
In the posted lower diagram, the horizontal 44.85 and 59.4 are listed in the 74 book as 46.63 and 56.5
