Gear ratio advice 3:73 or 4:30 on Super Duty

The point is that running power through gears produces heat. The less you speed up and slow down shafts the more efficient you are at getting that power to the pavement. This is why the engineers have designed overdrive gears into transmissions. The idea is that when high power is required the transmission will drop out of the overdrive gears to increase the engine rpm and run the power through gears closer to direct. So when high power is required it is better to be running in 4th gear at 2770 rpm and 60 mph with 3.73 rear gears than to be running 60 mph in 5th gear with 4.30 gears at 2387 engine rpm. For one thing the engine can produce more power at 2770 rpm than it can at 2387 and secondly the prpeller shaft is not being uneccessarily sped up just to be slowed back down by the rear end. I'm not saying that your set up is not going to work but I am saying that for lighter trailers such as all but the very heaviest of RV's 3.73 gears are a better choice than 4.30 gears with the new powerful diesels.