Hey everyone, guess what? RNG is random! There will be a certain range of monster levels that drop it, but beyond that there is no way to narrow it down.
This is one of the most sought after items in the game and based on how Blizzard has been nerfing farming locations, you really think they'd make it easy to farm this one?
tl;dr - LOL! You would think that D3 is the first video game any of you ever played.