The U-joints often dry out before they really get bad. A tip off, is a ring of rust dust right around the rubber seal for the cap (get a flashlight and get your eyeball close).
Double check your lug nut torque. Many of the newer replacement hubs I have seen, have the 1/2 inch threads all the way to the bottom of the stud. The hole in the disc is 15 MM (1/2" is close to 12.5 MM), there is some room for movement there, if the lug nuts aren't tight. If the 15MM raised portion (base) of the OEM stud is a bushing, I sure don't know, as they looked to be one piece, I've never seen a bushing or sleeve in any parts cataloge, for the stud base.
Usually whatever is happening with a U-joint it gets worse with the steering wheel turned to near right or left lock.
The last hub I put on, the bearings weren't seated all the way, I tightened to spec. (180), and felt the bearing slip into place. The bearing got really tight and I could hardly turn the tire. I backed off the torque to around 150 and ran it for a week and then rechecked the torque. Maybe raise a tire off the ground and check for resistance in the bearings. Too tight is often worse than too loose for longevity.
Your not the first to notice a click in the Fedral Mogul front replacement hubs. Mine have been in for a year now, the click from the bearings seems to have mostly disappeared.
Take a close look at the rear (rear of the hub) seal and seal race. Seating depth seems to be different between some after market hubs and OEM. Make sure the seal race didn't get bumped to a canted position, they can be a millimeter or two off, but anymore than that may cause problems (It could be hitting).
If there is excess play in the stub shaft and splins, it may be obvious when looking at the rear seal and race and rotating the tire/hub.
