I have never heard of anyone selling CV spacers. The way the axle sits in there that is nonsense. But they prob did mean the diff drop. It will help a little but not that much, just helps. Pretty much on any of the toyotas if you lift the front over actual 2.5" that is where you run in to CV problems. A true 3" lift while does clear tires also inherently hurts the CV boots and the joint it self. Generally they last long enough and replacement axles can usually be found pretty cheap, so if you don't mind replacing them once in a while its no big deal.