IIRC, the 100K plugs did not come on scene until late '13, or early '14. The build date on my '14 was 09/13, and it has the iridiums. Before that, they were Champion coppers with a 30K interval. You can run them 50K, but I would consider that the limit.
Factory plugs for the 2012 5.7L are NGK LZFR5C-11 (Gap 0.043 in.). Scheduled replacement is every 30K miles. They're copper core plugs with nickel electrodes. Torque is 18.5 - 22 ft. lbs. depending on whether they are installed wet or dry. I installed mine wet (anti-seize grease) at 19 ft. lbs. NGK says the threads have a metal plating that provides anti-corrosion and anti-seizing; so they can be installed dry. The factory installed plugs were installed dry ... but the Hemi heads are aluminum so I prefer to put a little anti-seize grease on the threads. Whether you install the plugs wet or dry, apply dielectric grease to the inside of the spark plug boots.