4 door to 2 door back glass 74 dart

will the back glass from a 4 door 74 dart fit in a 2 door 74 dart,
No it won't.
It is too short.
On a 4 door of these years, the rear window is more straight up and down than the 2 door and the roof is shaped differently.
Same goes for the windshield.
Just get out a tape measure and do a quick comparison.
And of course, the Duster/Dart Sport is totally different than the 2 doors and 4 doors.