I've heard of it, but why do it? If cross drilling a crankshaft makes it weak, I wonder what turning it down that far does for it. 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.