Are you guys suggesting to run multiple turns of preload? That has always made the car run horribly, and occasionally bend valves. My vote is for crappy parts. I have a Comp set of lifters in my truck that there are two lifters that will clack like a machine gun here and there, One day its fine, 3 days later will clack, 2 days later will go away for a while then come back a couple of days later. The clacking begins an ends on start-up. I have isolated them dis assembled them and nothing there, just in my opinion a poor valving design, a plate instead of a steel ball. Been like this since 2003.