I pull a 3023 easily at 55 mph over (Utah) mountain passes and 70 on flats with a '98 4.0 OHV Explorer Sport 4x4 (2 doors, short version)- it has 4.10 axles and WDH (big 33" dia off-road tires make the gearing more like a 3.8 axle btw). The combo is very stable.
The engine/5-speed transmission does an excellent job keeping the motor in the torque band as needed. FWIW, Id prefer the better gas mileage with the 6 all-the-time over getting an occasional 5-10 mph more with a V8. I get around 17 mpg, dont know how economical the current crop of larger V8's are.
Id probably go for a wider TV if I ever need more power than my current vehicle- point is, the Ford 4.0 six does a good job towing medium loads like our TM's- you probably won't need to change to a larger TV unless you want to for other reasons.
