If you are using an aftermarket style rocker like I am here, you need to lock the center lock nut on each adjusting nut at the point that you adjusted the rocker. To do this, rotate the pushrod in your fingers with one hand while you bring the nut down on the rocker with your other hand. As soon as you feel the pushrod drag a bit in the rocker arm pushrod seat it is at 0 lash, now all you need to do is add the preload on the rocker that is needed. I do not do the 1/2 to 3/4 turn additional that Crane recomends, rather I do 1/4 turn past 0 lash. I do this because I have had experiances in the past where I get hydraulic pump up at higher RPM's with hydraulic lifters that were turned 1/2 to 3/4 turn. Its my own little rule. I wouls strongly suggest you follow the cam/lifter manufacture's installation instructions.