On the Build Your Own I checked you could select the 6.2 and then had a choice of Off Road, Max Towing and something else. I selected Off Road and the 3:42 stayed in. If Max Towing is selected the 3:73 comes in. Didn't have time to try the third option. So depending on how the dealer ordered I suspect the 3:42 could be there along with the 6.2
I did it again and you're correct. It looks like the Off Road package IS 3:42. I thought 6.2= Max Tow Package which= 3:73. Whew... GM and their options. I've worked at four assembly plants in the last eleven years and the option list grows every year. I never thought I'd see the day you could get heated leather seats, navigation, back up cameras, and dual temp controll on a pickup. America loves choices and GM tries to offer a truck for everyone.