We did it with BLM RDM WHM SAM PLD RNG. The RNG was level 67, tops. I think the WHM was 72 and the rest of us were 74 and 75. So it can be done. We beat it in about 45 seconds or so.

And I have to agree with Septimus, it's a lot of fun for a RDM to be a DD for a change.