05 dodge 5.9 cummins reliability?

You really can't go wrong with that truck, especially the motor :)... unless you need alot of payload capacity. In which case, look for the same truck, but in a 3500 with dual rear wheels. The 2500 series diesels don't have much GVWR (about 8800) or rear axle weight capacity (about 6000), compared to their unloaded curb weight (about 7000 for a quad cab 4wd diesel), to give alot of payload capacity (only about 2000). The 1-ton dually version has about 11,000 GVWR, about 8000 rear axle weight rating and about 3500 lb payload capacity, for a quad cab 4wd diesel.