Everything on this engine is speedy!!
According to S&S, the lifter will work in either orientation so long as the roller is aligned with the cam lobe. In looking at the lifter, you will see that it is “waisted” (indented around the middle). This allows oil to flow around it and flow into the hole in the side of the lifter.
Good practice is put it back as it was (stay with established wear pattern), otherwise, align it to operate properly on the cam and push back up into the bore.