I've not come across any literature dealing with the design aspects of the 60-66trucks. I read somewhere a long time ago that John DeLorean had worked on the design but have no proof of this statement.
Dodge ran their stepside fenders from something like 53- 85.
Ford 57-72
Chev/GMC 55-66
Perhaps you already know 60-63 had an under dash A/C unit.