After working with the rockers 4x in the near past few days, the rockers can be adjusted to clacking, then zero and 3/4 turn with no clacking on the rocker. However, the knocking sound still persist.

It has a high volume oil pump and each rocker pumps out a ton of oil. I examined each rocker and they all seem to pump equally and raise up and down fairly equal.

So one question still remains. Can a lifter make this noise if the rocker is properly adjusted and does not make any clacking?