Rear window
That's not exactly true. All of the windows will swap out 1973-1996, however there are a few differences.
The Solid glass on the 1973-1979 is thicker than on the 1980-1996 trucks, and there is a different seal used with different part numbers. They are swappable if the right seal is used for the glass you use. Ford used the 1980-1996 window and seal as a service replacement 1973-1996, but there are fitment problems without the apropriate seal.
Slider windows are year correct 1973-1981.
The slider changed in 1982. and fit 1982-1996. However those are swappable between the years as well, if the apropriate seal is used. Just looks weird in an older truck.

There is also a question of tint. Tint on the windows changed throughout the years, and your truck may not have tint, or vise versa. To get the right tint match, you can match the numbers etched on the glass, and the words tint or "SUN-X" for tinted windows, etc....

Hope this helps



