Swapped engine but knocking noise persists, pulley issue?

I recently swapped my old 3.4l for a new JDM one because it was supposedly knocking. I recently put a screwdriver to the oilpan to make sure anything was sound and found that the same-ish knocking was still there. Not loud at all but same symptoms. ( only knocks when car is in gear or under load at idle). I replaced the harmonic balancer along with all the belts in hopes of quelling the noise- and for a few days it did. After this the noise came back. I swapped over all of my old accessories ( water pump- oil pump ect.) So I'm thinking one of the pulleys is making the noise. Does anyone have any experience with this issue. It's driving me absolutely insane.

 

No experience specific with this kind of issue, but I will say an automotive stethoscope would likely be more helpful than a screwdriver alone to track down this noise. They run about $10 or so at most parts stores and are worth their weight in gold.

 

I'm on my way to autozone right now

 

Nice. Good luck finding the noise, and be sure to report back your findings in case it helps others down the road