correct, thick gears are for gears such as 5.13s working on 4.10 and down carriers.
from my readings, the teeth themselves arent stronger, the whole ring is just thicker.
99 WJ hp44, 3 link, Eaton e locker, 14" foa coilovers in the front. 14 bolt, 4 link, grizzly locker, 12" foa coilovers in the rear. 5.38s and 37s