Right now I TR my old Sorc and now have a L3 wiz. With the release of the Sorc PRE, decided I want to switch back to Sorc.

Before purchasing the +3 wood, saw it had a L7 requirement. So in my case, I should level up to level 7 with 4 levels of sorc before using the wood? So L3 Wiz/L4 Sorc, then use the +3 wood to change the 3 level wiz to sorc?