80-85 with RAF is a breeze. You boost 4 alts with a 90 in Stonecore. It's almost a level a run. 6 runs from 80-85. Takes a little over an hour.

Make sure to buy the level 80 starter Cata gear in Hyjal just so you can survive if you get hit. Otherwise leave your guys WAY back and don't attack anything. You don't even need to be in the closed room with the boss fights to get exp.