For anyone looking to still do this, the head enchant make the item you use it on soulbound now and the leg enchants don't work until you are the appropriate level.
I believe you dont get the full spellpower coefficient on low levels. Unless its different in tbc, i believe 1 spellpower results in 1 damage from level 20 and above. On lvl 1-10 you will only see your spells do 2-3 damage extra in total. Not fully sure but it’s something like that at least
