Max, to answer your question, I am running a 195 degree AC-Delco stat in my 6.2L. It runs about 200 degrees at all times. The injection timing is a bit advanced to try and pick up some power, along with a slight increase in fuelling. Its the worst when you are just idling around, but will continue to smoke if you are keeping it in 2nd gear / low range at about 1500 rpm or so.
Once I hit the highway again and start driving normally, the bluish grey smoke dissapears right away, only coming back as a very light bluish / black haze if you've got it pinned trying to keep speed up a hill.
Once you idle for a few minutes, the smoke comes back again, and doesn't go away till you start to move again.
I know the engine is a bit low on compression, it does have around 200 000 miles on it.