I've got an 01.5 with 102k on it and just replaced the 2nd ball joint track bar with a Titan Adjustable bar from Cummins Performance Parts and a new drag link (Moog) from Napa. What a huge improvement! I can drive with one hand again!
The original ball joints I had replaced at about 70k miles and they have zerks. Oh and btw for folks wondering, these parts are all replaceable on your own if you have some mechanical ability. The only reason I paid to get the ball joints done was due to time and it was the middle of Fairbanks winter and didn't want to leave my daily driver parked outside long enough to fix the truck.