I bought mine from David Lynn as well. Great product, beefy. I believe you can order them from JLP now as well, although they mark them up.
I had the clunk bad, took it into Hawkinson Ford for a fix (with the clunk washers). Bad idea. Not only did they wholly ignore my request to install the clunk washers instead of the star washer fix the TSB calls for (after telling me it wouldn't be a problem), but when they went to align it they didn't align it correctly, and told me it was because I had snow tires on! Unreal!
Sure enough, I got the clunk back after a few hundred miles. This past weekend I put in new springs and installed the clunk washers at the same time. Again, unbelieveably, Hawkinson NEVER INSTALLED the star washers they were supposed to per the TSB. They just cranked the hell out of the bolt with a torque wrench (way past the 140 ft-lb specs) and left it. I will never go to Hawkinson again.
But so far, no more clunk!