If I were a betting man, I'd say that you have a leak from the headgasket cooling port into a cylinder. You mentioned it "using" coolant. Also, if it has a propensity to blow coolant from the overflow bottle, what I have described can be the cause as well. (Cylinder compression, pressurizing coolant system). A pressure test may show ok, with either failure.
You might look at the FSM for the torq. sequence and run the torq on the headbolts again, maybe 105 ftlbs max.
The overheating may have caused the head to warp or if its wasn't too flat to begin with, the overheating caused enough movement to break the gasket to metal seal on the block or head.
I would find a friend or a shop to ck. the block and head for flatness with a straight edge.
Also if the head comes off, drop the valves and check for valve seat cracking. Look at the appropriate Dodge/Cummins service literature to determine, if its time to scrap the head or find a cast iron welding guru and a machine shop to re-grind the valve seats. While its apart, I'd do valve stem seals too.
If I have properly diagnosed your concern, here's what 80,000 mile cylinder walls look like after continued operation with it using coolant as you describe. So just adding coolant only causes more extensive damage for the future.
Good luck
Andy