It appears the OP was just venting, and or looking for some magic beans with which to fix his truck. 1 n done on this thread probably.
I'm presuming one of the components failed, took out the belt which took out the other (probably water pump murdered the fan with a thrown belt). Regardless, without more info, who knows....
Heck, maybe the new t-stat aint opening all the way, causing the engine to run hotter and thus the fan to be working overtime.
I don't think an old Hemi has any de-fueling due to temperature built in. 06 6.1 Hemi Charger we had, went about 2 years with increasingly failing electric fans. To the point only one of them would work at low speed and the other didn't respond. That car would still chit and get even though under the right conditions it would run around 230 degree coolant temp, until I replaced the fan assembly.