rocker arms adjustment

I have measured the required movement of pushrod with a dial indicator. one full turn is way too much preload, one quarter turn will produce .050 preload on the lifter. I run a 340 with adjustable rockers and hyd. lifters in a race motor. preload becomes critical if not done precisely. too much preload, will cause pump up. If you don't mind a very little valve noise, set them at zero lash. it's a better method anyway.