The problem is that in theory, the 72-93 were all D/W trucks. So people think they were all interchangeable. Which technically is true, but the differences are everywhere. The entire body and frames will bolt right on, just wouldn’t have the body lines match and in some cases, the interiors are so vastly different it causes issues.
But here’s a fun fact, the body mounts on a say 78 dodge power wagon, regular cab, long bed, are in a location that allows the body in it’s entirety to drop down and bolt right onto a 2003-2010 Ram 2500 regular cab long bed or an quad cab short bed chassis…