Some thoughts about gearing:
In the world of trucks, a numerically higher final drive ratio is only needed to get the load moving. This can be achieved one of two ways: a high ratio rear end or a high ratio first gear in the transmission (remember the granny gear in old trucks with manual transmissions?). The problem with the high ratio rear end is it never changes, which affects rpms with all remaining transmission gears. In racing, this can be a good thing, but it trucks it isn't. By using a lower ratio, manufacturers can achieve better fuel mileage, which suffered when DPF systems were added. As mentioned by a few folks, the new trucks also have more torque, which coupled with the low first gear, negates the need for a high ratio rear end gear.
In other words, try it, you'll like it!