Pala Holy, well known CustomClass, plugin for interrupts, use only stun and trinket by your own, and stay close to partner all the time. if partner has gear and is not noob, easily 1750/2200
For example, when you receive 2-3 CC in a row, you can have a 0,2 sec. delay between them, if partner is close you can crit on him with 30-40k in this time.
Best partner for me:
Mage
Cat
DK was also OK, but long fights, you need patience, 30-60 minutes one run.