I personally don't know of anyone who has or had a crankshaft turned more than 0.010". And a block that's been bored 0.060" can't be bored again without being sleeved. I think that I heard that they turn down the journals that far so they can use chevy rods.
dan, you did know that cars rolled off the assembly line with factory produced engines that were 10 on the crank, or 20 over on the cylinder, right? you think there wasn't ones rolling out that weren't 20 or 30?
yes, before the advent of cheap and/or available stroker kits cutting the journals for chevy rods was a common practice, as was offset grinding mains for more stroke. and that's offset grinding cast cranks.