Thank you all for the good info! I have been swapping 3/4 ton stuff into 1/2 tons for years. this is my first expedition into 1 ton and larger. Seeing how I have 2 M1010s, I think what i am going to do is find some 1 ton dually axles and change everything over to single wheel. I am going to do a shackle flip kit, steering box brace, and 38 inch tires with a 3 inch body lift kit also. I do not want to butcher the body, and have the ability to return it back to stock. what do you all think?
IIRC, 1 tons have 40" perch spacing, 3/4 and 1/2 tons have 42".
If you want single rear wheel, why not just use the housing you have and swap gears? A dually width axle is going to be too wide. You're going to have to pull the carrier anyway assuming you want to put your existing Detroit Locker into your replacement axle. 14 bolts aren't terribly difficult to swap gears in and around here you can buy an entire junkyard rear for about $150. 3.73's are about right for stock size tires, but if you're going with 38" tires I'd leave the 4.56's in it. Either way you go it's not an ideal highway cruiser.
3.73 gears with 235/85-16 (~31-3/4" dia) tire = 72 mph @ 3000 rpm
4.56 gears with 38" dia tire = 74 mph @ 3000 rpm
The ideal (but expensive) fix is to swap gears AND swap the transmission or install an aftermarket overdrive. 4.10's with a gear vendors overdrive or 4L80e is almost perfect for all around use with the 6.2 and <33" tires. Only downfall is that you're looking at around $4k just in parts.
I'd avoid a body lift if at all possible. If you just need a little tire clearance, skip the body lift and trim the front fenders. Costs nothing and it is a more effective fix.