FBinNY, thanks for the idea. I just checked the cups and they are in there nice and tight. No movement at all.

dabac, I had thought that might be the case too, however, when I checked out the cups and the headtube I saw there was plenty of threads left. I can adjust the bearing ever tighter but that only results in steering that won't self center. I almost think that the upper race (the lower nut that adjusts the preload-whatever that's called) might be the problem. This headset, a Toro brand with a allen key clamp type of lock nut, was always super sensitive to how tight you put the lock nut on. It will feel almost perfect until you start to tighten the allen key. Then, the steering gets too tight. It's a weird design. I think that tightening the allen key warps the upper race or whatever resulting in the play or stiffness. I don't know.