Did some research and it seems like the lifter should collapse .020-.060 according to Crane Cams, other sources say .030, which is also what Sparks had mentioned.
Since I have my side covers off and it's on an engine stand, I'm just going to use my calipers to measure the preload on the lifter. Should be able to set them without worrying about 1/4 turn or 1/2 turn or full turn or....!