The last revision on the factory specifications was back near the end of 1990 I believe. It set rod and mains the same @ min. .0008 and max .0022. I tend to agree with that as it pertains to all but a full race application. The thing I believe to be very important is to make sure the variance between all the rods, and or all the mains remains within .0001/.0002 in. That can be a very time consuming job if you don't have alot of sizes to choose from by the bearing manufacturer. Most serious engine builders will have a specific spec that they feel comfortable with for each application.
Danny