Duster fuel filler pipe difference between years

as stated , much of it has to do with also using the proper cap.
If you dont need the ECS junk, then steer away from 70-71 tube, as they will have the vent line on the tube and caps are a bit harder to come by.
I have swapped the folding rear seat version tube into later non-equipped cars, as I like that version better, but all should swap/fit in the same, just use the correct cap.