The 6.0L is about 300HP/360ft-lbs from what I could find, not that amazing from a 6.0L V8, but I'm guessing the torque curve is probably pretty flat.
It will be a pain to install though, you are putting a 3/4 Ton GM drivetrain into a midsize Dodge truck. All your engine/tranny mounts will need to be redone, plus the wiring harness will be much more difficult to swap over. That engine uses drive by wire I believe, so even your throttle cable won't be of any use, you'll need to swap in the GM pedal.
IMHO you would be further ahead swapping in an OBD I 5.9L Magnum and throwing in cam/headers with a MP PCM. It would just drop in with minimal rework as everything lines up. When you are going to that significant of a change, pretty much everything is going to need to be looked at and custom made.
You got the truck for $1000, but that doesn't count any custom mounts, brackets, driveshaft, etc. that you will need and your time it will take. This definately will not be considered "easy" power.