My DK team cleared Gundrak today, was a lot easier than I thought it would be... We are all 76 and after clearing it I decided to check the boss levels on wowhead. 78! Lol I didnt even notice. I can see the last boss being really ugly in heroic though. ;(

edit: two guys died on last boss because I forgot that impale means they have to be healed to full. Woops!