You are correct it's the 42rle auto. It does seem like a steep gear but it is ideal for this tranny because of the .69 overdrive it has.
60mph - 2,250rpm
70mph - 2,600rpm
Right where the 4.0 is happy.
I ran my first tank in the city with only about 5 miles highway to break in the gears. My gas mileage increased noticeably. I went as far on 3/4 of a tank in the city as I used to get out of a full tank (to red warning indicator) on the highway. Haven't checked mpg's to find out what the actual increase is.
BDS Springs, MetalCloak Arms, Fox Shocks, Warn Winch, Savvy Ft Bumper, Antirock, GenRight Fenders, GR8 Top, Rock Hard Cage, Banks Exhaust, 5.13's, Revolution Axle Shafts, LS-III, 4L80e