what was in the duster?
do both cars have the same transmission?
are you swapping the transmission?
edit: WATERPUMP
your dart has the waterpump exiting on the passenger side
the duster has the waterpump exiting on the driver side
you can simply swap waterpumps BUT that would hide the timing marks on the timing cover
no issue IF the engine is running great and the timing doesnt need to be addressed but i would swap the timing cover and install a water pump to match
(or take the radiator from the dart and bolt it into the duster)