it disenchants from greens with an item level of 41-47 ish, i am busy farming 1 mob at the minute that has a timer of 80 second he drops 1 green every kill, however a dungeon of this level maybe more lucrative.....where should i go
Normally a mob drops items with an itemlevel around its own level, so Zul'Farrak / Stratholme would be places to try. Remember to loot everything and sell valuable stuff, or else it would most likely be better to just buy from AH. In the end, buying from AH after getting gold the best way you can will most likely be the most effective way of getting something.
So make portal to dala then take the portal from there to tanaris and fly to ZF.
Another good way is to buying green items around that itemlvl you need from ah if they are cheap and DE.