You are correct on the Ford Power Strokes, they require SCA's (Supplemental Coolant Additives) as they suffer from cavitation however the B series Cummins, (the family that the 5.9 Dodge is part of) according to factory service bulletins, do not suffer from cavitation and don't need additives. There is debate as to the value of adding SCA's to all engines irregardless if they cavitate or not and the possibility of causing slow heat transfer to the coolant because of the layering affect of the SCA that isn't stripped away regularly by cavitation.
Here is the Cummins service notice on SCA's:
Operation and Maintenance Manual, B Series Engines, Bulletin No. 3810205.
The B Series engine normally does not require SCA because the engine normally does not experience cast-iron cavitation corrosion. The Cummins B Series engine has not shown any tendency toward cast-iron cavitation corrosion. Also, the B Series engine does not have an integral coolant filter.
Therefore, the B Series engine coolant recommendation is to use low-silicate antifreeze meeting ASTM D4985 specifications and to drain and replace it every 320,000 km [200,000 mi], 2 years, or 6000 hours of operation (whichever occurred first).