Some differences that nobody has mentioned yet. The heater opening in the firewall changed in 1981. So 73-80 cabs use the early heater and 81-93 cabs have a different opening. Plus the square hole for the main wiring harness changed a couple times.
The wiper motor also moved over a bit in the 80's. later truck got a hydraulic clutch so there is holes for that to consider for your earlier truck.
The late cabs have an integral floor hump where the earlier cabs have a removable hump on 4 speed and 4x4 cabs. There are small and large humps too.
The 90-93 cabs are made of lighter metal and dent easier. The rockers got sealed up in those years to prevent dust from entering, but it resulted in rusted out rockers which wasn't really an issue on the 73-82 trucks, especially the 81-82 models which Chrysler went galvanized crazy on for a couple years.
The best cab for your truck would be a 73-80 with the appropriate floor hump