I bought the '06 Cummins 4wd quad cab w. 42K miles for a damn good price about 10 years ago. The 5.9 runs perfect...only problems under the hood have been the AC compressor locking up and ruining the serpentine belt (fixed)...and coolant leaking at the fitting on the back of the block (will be fixed). Oil and fuel filter change every 7-8K
The truck's biggest issue has been the dreaded 'death wobble', which would only go away with new tires. I plan on replacing the older steering linkage with the newer heavy duty parts. Have everything needed...waiting for warm weather.
Drivetrain...warranty covered a bad bearing in the transfer case, and the transmission tailshaft cracked because of a u-joint failure. Had that replaced. I put in a new driveshaft for insurance.
The fuel system has been problem-free so far, but I do want to put a lift pump outside of the tank ..any advice/suggestions on which brands?? I was lucky to find a spare Reman. MoPar- Bosch pump for cheap at a swap meet. Good to have a spare.
As far as body...Illinois sucks, period...and the weather has been hard on the sheet metal. I'm on the hunt for a rust free bed and a rear pass. door (anyone have those in silver to sell??)

Other plans include new exhaust, and gooseneck hitch. Maybe aftermaket heavy duty bumpers