Good Evening, Walter,
My Kodak data sheet from 1976 gives the speed as ASA 1250. Tray development in HC-110B with continuous agitation is 8 minutes (68 degrees). My own experience in film developing would indicate that Kodak's "continuous agitation" times tend to work well with development in rotary drums also. The data sheet has lots more information, of course; if you need more, just PM. I'll photocopy and mail the whole sheet if you wish.
Years ago, I used a few rolls of this emulsion in 120; it should be named Royal Grain. What you have is likely to be very old with, consequently, a very high fog level. Good luck!