Swithrow:
If you have a stock trans pan and you let the truck sit overnight or longer before changing, you can expect to add 8. 25 qts if you change the filter and 7qts, 12 oz if you dont change the filter.
If you drain it right after driving it, the fill amount is 6 qts exactly with a filter change.
Going from the low mark on the dipstick to the full mark is only like 8 to 12 oz so don't overfill.
When adding after a drain, I would only add 7 qts (w/o filter change) and 8 qts (with filter change), drive it to get it warm and then check and add as needed for the overnight period.
Also, the most accurate way to determine the correct amount is to put the old drained fluid into 1gal milk jugs and see how much you drained.
I have drained my fluid many times...
BTW - Schucks carries Valvoline Sythentic ATF+4 for $4. 95 per quart. I always buy a case when changing the fluids...
Gasket is reusable for many changes (good job Dodge!!)
Good luck, take your time and don't overtorque the filter screws. Spec is 35 in-lbs, pan bolts are 13 ft-lbs.