I have a friend with an M1010 with 6.2 turbo'd, 5spd (i believe a 4500 but not positive), 4.10s, on 35s. He says it'll cruise at 70-75 no problem. I've been considering the 4.10 swap for my M1010 (currently all stock), but I think I'm going to wait until after I lift it and put 35-38" tires to see how the stock gears/motor pull it. Eventually it'll get repowered, (most likely with a mild sbc, maybe a 4bt). I'm undecided on the transmission tho. I want at least a 4spd auto, but I don't want to deal with needing a computer to control it. I like the idea of a 700r4, but they're reputation of failing in big truck applications worries me.