Direction of the oil port on lifter

[PKRWUD]

I understand what you're asking now (it was the outboard comment that did it). I was tripping on how you thought you were going to put a roller lifter in "upside down"!! You can install it either way. The recessed groove that surrounds the lifter body will fill with pressurized oil, and once that happens, the hydraulic effect will keep the same pressure through it regardless of the holes location. Good question! No one has ever asked me that one before.

Take care,
-Chris