You are correct. 392 Rubicon has 3.73 and 392XR on 35's has 4.56 with a monroney that shows 3.73 in the standard equipment column. On the XR option list it doesn't call out the 4.56, which drove a massive back-and-forth on the Jeep forums in the early days of the XR option.
Haven't seen a recent sticker so can't speak to the 4.56 being called out...but the 35's from the factory have them. For Jeep fans this vehicle has been a grail for a very long time. If you've ever been in one, it is a riot!
The 392 does 60 in the mid 4's. The XR does it in 4.0 and the quarter in 12.9/104 mph (on 35" off road tires
) The 392 is governed a notch below 100 mph, XR goes to112. I'd stick with our Challengers and Chargers for higher speeds...the suspension in a Rubicon is designed for something else entirely!
Jeep fans run a wide ranging gamut from hard core off roaders to mall crawlers/chill dudes just as our ilk runs from the serious folks on this forum to the street takeover crowd. Oh...and everyone loves mods.