Sorry. When I mentioned that my JKU has a 3.73 with the Max Tow Package, I forgot to mention that I do not have a Rubicon. I have a Sport.
I you go on the Jeep site and build a Rubicon, I seems as though the 4.10 is standard, even it you don't choose the Max Tow Package. I believe that you have to actually choose the 3.73 option to get it.