Sadly, the legacy of the Dana 35 endures!
EDIT: But Rubicon model is 44, and tow package provides 44.
EDIT EDIT: "All three axles (Dana 30, 35 and 44) are wider, of course, to match the wider body of the Jeep. The Dana 44 is actually upgraded so much that the engineers really wanted a new name for them. One Jeep rep. even suggested that it should be a "Dana 45," but of course, at this time it is not. The gears are larger, the pinion is larger and the shafts are now 32 spline instead of 30 spline. Rubicons still get a similar locker, though it is a bit larger than the TJ's." - Mike Cohn, Rockcrawler.com