Power-Lock units don't have friction material on them like the Trac-loc units do. I've rebuilt a bunch of Power-Lock units with the current plain coated plates with good results.
Make sure you coat each disc and plate with friction modifier when you re-assemble it. Remember to use red Lock-Tite on the threads and I use a spot of ARP lube under the head of the bolts so they don't gall.

Gus