If your priming lifters for engine assy, so they won't be dry,.....I place them in a can , one at a time,....... with the same oil I'm gonna use in the engine,......use an old pushrod and "stroke" the lifter till it pumps up as full as possible,I leave them standing upright submerged in the oil until I'm ready to button up the motor, repump them one more time,then install,........if you have adjustable rocker arms w/hyd. lifters and your going to set the lash (cold) the lifters will need to be pumped up, in a fresh eng build, you'll need to preoil the engine, be sure to rotate the crank to supply oil to the proper passages