I can't say for sure, but I can say that when I bought Raybestos PG hub and rotor assemblies for my eight lug 250 they did have races installed.
Maybe a local parts store has those in stock?
Have them pull it off the shelf so you can look at that same part number and see for sure that they come installed.
Also know that new races should always be seated by over tightening the hub, spinning it by hand, then backing off and setting the right torque, or drag.
Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.