Nope, the OP did mean 6060 for a M1010 camper build. I am wanting to be able to do highway speeds and some off road but nothing hard....just don't want to get stuck. The truck has the TH400 in it now and will only do 55 mph without over revving the engine on the road.
If you ever want to go off the pavement, a tr6060 is the wrong transmission. You need a truck transmission with a low first gear, or an automatic, or if you use a manual car transmission with car gear ratios you need at least 4:1 reduction in the transfer case (or a doubler). Autos can get away without a low first because the torque converter can slip below the lockup speed, but a manual must have low gearing or you will burn through clutches in a hurry no matter how good of a driver you are. Without deep gears it's just not possible to go slow enough whenever there's an obstacle without burning up the clutch.
Another thing to keep in mind, since you are planning to do road trips in this truck. From someone who owns and loves several square bodies, remember these vehicles are wildly uncivilized compared to new trucks and make sure you and all your passengers are ready for that.
I've daily driven my 1009 for 6 years and do 1000+ mile road trips in it several times a year along with dozens of 400+ mile trips. I've spent over $20k in parts and hundreds of hours of labor installing an overdrive unit, low geared manual transmission and matching transfer case, new axle gears/air lockers, a turbo, a nice interior, AC, seat heaters, literally hundreds of lbs of sound and heat proofing insulation, an intercom/headsets out of a Cessna aircraft, solar/fridge/stove/running water/compressed air/a welder and every other driving and camping creature comfort I can imagine. You still need headsets to carry a conversation at 70 mph, the AC doesn't work nearly as well as a modern truck, even with the turbo the engine is underpowered compared to anything made in the last 20 years, and the fuel economy is worse than a new truck. Some of my friends won't even ride in it for more than a couple hours.
I love how simple it is to work on, I enjoy designing and building all the various parts and upgrades, and I love the classic body lines. But just remember at the end of the day, you'll still have a crappy old truck that is slow, loud, and handles like a 70s Chevy. For not much more money I could have had a Tacoma or Colorado that would be much more comfortable and get better MPG. Every minute I spend on the highway I wish the truck was more comfortable and had another 100-200hp. But when I get off road in the rocks, throw the SM465 into low, hit the lockers, and get the turbo spooled up I remember why I drive a CUCV. All this to say, really think about your goals and what it would take to get there. It won't be cheap to make an old bare bones military truck into a comfortable highway cruiser; trust me I tried and am still trying lol