I can help... even though those "free" D60 gears you sent me had a tooth chipped off the pinion.
I have some 7/8-18 LH & RH inserts with hexes for $13 ea. You might have a problem with weld-in's though. The weld in bungs require 1" ID tube. If you were running 38" or smaller tires, you'd be OK with 1.25"OD x 1/8" wall DOM. But you're running 42's. I'd say you're gonna need at least 1/4" wall tube. That makes the OD 1.5". That's pretty huge. I have some of that if you want it, but I think you'd be better off having some 1.25"OD x 1/4"wall drilled and tapped.
If you're interested, let me know which way you want to go and I'll get you some prices.