I can't say 8-10 hours is impossible but you have to be hitting the instance caps at that point. Maybe mix in some instance quests and it's probably possible. My personal experience was a little over 15hrs. looting only a couple items in SM. 1-2 random bosses in stratholme. Skul and Hearthglen or whatever NPC if they are in my path. That also was the group that I did not bother to get any skills on until they hit 60.