re: 3-2-1 Ribs

Every rack of ribs is different. Use 3-2-1 as a guideline for the following:

3 - Cook until you like the color
2 - Wrap and cook until the meat retracts, exposing about 3/4 to 1 inch of the bones. Practice will let you determine how to get the right pull based on the amount of exposed bone. At this point the ribs are cooked.
1 - This is for finishing and putting on a glaze. The ribs may dry and firm up a little. I somethimes shorten this segment to 30-45 minutes when I don't use a glaze.