With a welder and sufficient fab work, you could put a Pinto body onto it.
However, the wheelbases are different and I'm sure the body mounts are in different places, so no, it won't bolt on.
The 69-72 frames are one style; 73-77 another, and 78-91 are similar to the 73-77 but differ in the middle where the rear seat/floor changed.
-- A