Upgrade magic Armor

[Cassiel]

I recently looted my first Upgrade recipe, Upgrade Magic Armor. I got the Awesome Plate of Sorcery Ancient Plate lve 167 & upgraded it to lvl 317 armor class. One downside is that now I need to be a lvl 41 to wear it. I'm lvl 38. Same thing happened to another plate. Is there a conversion chart to show what lvl you need to be to wear upgraded armor?

[SamAlchemist]

I thought it followed Diablo II, but appears not. Looks like a hybrid progression table was created by the programmer.

[Kosiciel]

Makes sense, because exceptional items (tier 2 here) all required max level 25 to be quipped, and that would be to soon for top ones.