Beautiful truck, and welcome to the full floating axle club!

Really glad you aren't going to give it the El Camino treatment.
Also, you might consider just a 4.10 third member and tall drive tires. (I think those are 245/75 tires you have now?) My truck has a 283, 33.5" tires, and a 4.10. It runs about 2,150RPM @ 50MPH. With shorter 235/85R16 radials it should still be around 2,250RPM at the same. You should be able to come up with a 4.10 third member for $100-200, and you don't even need to jack the truck up to change it.