I have ran a lockright in a 60 with a 6000 lb truck, no problem, Bigwoody has one in the front of his buggy, had to replace pins once, no other problems. Both of us have broken shafts, he's broken several.
I have seen two detroits break when a shaft let go, one was a 14 bolt, one a 9 in. They cost more, you have to set up the gears, I would not run one in a 60 even if money was no object.