Yes you can adjust them like any other lifter.

If I build a new street engine I usually adjust my lifters while the engine is on the stand with no intake on it. With the lifter on the backside of the cam I adjust the rocker arm till there is no play then about 1/2 turn on a performance hyd lifter engine. Just enuff that I can see the plunger down, away from the snap ring in the lifter. I can say, I do not get any lifter noise on new startups. After break in I then do a standard hot lash if I feel the need. Those little white buttons come in handy!! I got tired of dealing with hot oil and messy fenderwells, smoke and worst of all cleaning up the mess!!!