Check my
armory. I've started running heroics with this setup, and I'm still embarassing myself. I've cleared Heroic Ramps once, got kicked out of Heroic BF after the first pull once, and last night I got told I was a ****** tank and the healer left from another Heroic Ramps.
The more I do it the more I'm starting to realize that these instances are actually doable with my gear setup, but it takes some unorthodox strategies. If there's a 5 mob pull for example, there is -no way- I can tank 3 of them while 2 of them get CC'ed. Even if 3 of them get CC'ed, it's still going to be bad news usually. One possible solution? Have a hunter lay a trap, pull with multi-shot, run back to the start of the instance and feign death. Mage sheeps one. Now hunter probably has 2 mobs running after him, 1's sheeped, 1's trapped, and I'm tanking the 5th.
The point of this is that you ARE going to be embarassed at first while running heroics, since even simple pulls can sometimes require a different strategy than what you're accustomed to. You might wipe 7 or 8 times on your first full clear of a heroic.
That being said, you really should get 12k HP unbuffed. The normal mobs will hit for about 3-4k per hit. If you do something like Underbog or Mech where they have the really big mobs that tend to hit harder, it won't be uncommon for a single hit to do 4-6k.