FWIW, on my first two sets of 315's BFG's, they were mounted the stock 8" wheels. I got 40,000 out of the first set, and 42k on the second set, both sets were basicly slicks at the point when I replaced them. Both sets were rotated every 6,000 miles.
Then I tried 10" wheels, and the same 315 BFG's, I currently have 42,000 on this set, and I bet nearly half the tread is still there, I see no reason not to get 60k out of them. Keep in mind, since the truck was new, I have been constantly upgrading to more power, repeated burnouts, drag racing, and sled pulling. No other real changes have been made except for the 10" wheels, to which I atribute the increased mileage, since my driving habits haven't changed either, still drive it like I stole it.
I also have been rotating these every oil change (6k), they are flat as a board across the tread, no roundedness like on an 8" wheel, no funny wear pattern, and the truck drives straight as an arrow (even with my hands not on the steering wheel). The truck has NEVER had an alignment in it's life, and at over 120k on the clock, still doesn't need one.
Rob