That would be a matter of adjustment. The body parts from '72-'80 will all swap with a few exceptions like early beds not having a fuel tank inlet, different valance panels for different grilles and so on. Technically you could convert the entire truck over to the '80s body style since the cabs are basically the same and the later doors and fenders will bolt on. This is pretty common with CrewCabs since the '70s era CrewCabs are much more common. Odd fact is the rear doors on the CrewCabs are the same for a '70s and '80s model which is obvious when looking at the rear door handles. The rear doors have a little indention where the handles set like all the '70s era trucks while the '80s front doors do not. At any rate, converting to the later body style is possible, but not recommended unless you need to swap all those panels and get a good deal on a parts truck in good condition. Everything but the cab would need to be swapped, including the core support and grille. Technically the cabs are also a little different but it's mainly just a couple small bodylines on the roof and the cargo lamp on later '80s and early '90s models which is not very noticeable, even to Dodge truck purists.
But yeah, if your fenders and doors aren't matching up well, you should be able to adjust them by loosening the bolts, shifting it around a bit and adding or subtracting shims, usually at the cowl and bottom near the door. If you core support is bent up or the bottom has rusted out at the mounts, it can cause a lot of alignment issues due to it pulling the front clip down.