KH spindle w/late rotors

Another member has a full brake setup in the for sale section. In the ad they are using 70-72 spindles with and adapter inner bearing that allows the use of later rotors. Id like to know what bearing this is, and if I can truly use later rotors on my KH spindles.

While im on that subject, KH spindles, can i also use later lower ball joints on these spindles?