I guess I am still a bit confused by your question. EH and stam are directly intertwined, as stam is effectively half of EH. If you know you're lowering your EH by trading a large chunk of armor for an amount of stamina which doesn't actually make up for the EH lost by the armor, how are you actually helping your healers on Festergut? You'll have the HP to take the incoming damage and survive the max hits, as is (though it might be cutting it close). Removing armor for superfluous stamina isn't going to change that outcome. If you're worried about surviving Festergut, I would...
1) Change your chest enchant to 275 health.
2) Change your glove enchant to the armor kit (Glove Reinforcements).
3) Switch your shoulder enchant to the +30 stam PVP shoulder enchant.
4) There are a number of fairly easy to get tanking weapons, from Pit of Saron to Onyxia 10/25, or even ToC / ToGC 10. The Onyxia or ToC weapons will give you a nice little boost also.
5) I would say switch the two multi color gems in your chest to 30 stam gems, but I don't think the amount of +defense you have right now will allow it. Maybe after you get a weapon.
"Sometimes attaining the deepest familiarity with a question is our best substitute for actually having the answer." -- Brian Greene.