[Jeff Chambers]

I'd have to throw in this comment on the methods given above. To find the point of zero lash, spin the pushrod between your thumb and forefinger while slowly tightening the polylock. When you feel the first bit of drag on the spinning pushrod, stop tightening the polylock. This is the point of zero lash. Then set your desired preload from there, i.e. 1/2 turn, 3/4 turn or whatever you like to run. Ford recommends something like 0.040" to 0.060". On a 3/8-16UNC stud, one full turn is about 0.063". Some like to run it looser, some tighter. It all depends on how confident you are in your lifters and spring pressures.

To say "tighten until you can no longer rotate the pushrod" is wrong since that would imply that you've completely collasped the lifter and loaded the pushrod in compression.