This generation of ERVs came with 4.63 gears in the rear and since you cant get a Dana 60 front axle in 4.63 I planned to regear to 4.10 and spec the front axle the same but Chris noted that I could run 4.56 in the front since its close enough to the rear without causing any issues and with larger tires my rpms would be brought down to something more highway friendly and that's what I ended up doing.
So you will be running 4.63 in the rear axle, 4.56 in the front axle..... ??
Maybe it can be done in low traction situations but that is a BIG spread. My 1970s F250s all came with a 4.10 D44 front axle, 4.11 D60 rear axle....
Off road, gravel, forestry road all was good. 90% of the time I was empty. But hit pavement or even tarred road surfaces and the transfer case would HOWL..... you knew you could not run in 4WD on a hard surface.
Given you will NEVER be empty. You will be at a full 100% of GVWR.... I would match both axle ratios. Fully loaded 4WD will kill tire life. Something has to slip when the tires are turning different speeds.
Ford Owners Manuals TOLD you to shift out of 4WD with 4.10/4.11 ratios you had to back up for 15 feet to remove the driveline bind on the transfer case. With 4.56/4.63 you'll need to back up a quarter mile to remove the bind.
You are doing awesome work but I worry about the axle ratio spread..... Technically in 4WD with tires turning different speeds in low traction like on ice,,,, 4WD could lead to a loss of control.