Terry, you should be at about 3-5 foot pounds of torque on the head bearings.
As MBrane said, a LOT less than round rollers.
Not sure about your XJ, but my VFR specs 18 Ft/lbs for the head bearings, and if I torqued them to that setting, it has a wicked low speed weave.
Torque them to the original XJ spec, rotate the triple trees left/right/left several times, torque to the spec again, rotate, etc, THEN back them off and torque to 3 ft/lbs.
Maybe try 5 ft/lbs if that seems too loose.