Help diagnose knocking issue VIDEO

I am experiencing a loud rattle/knock which seems to occur at a specific RPM (maybe 1500-2000), then fades. Also it doesn't appear to be an issue at idle. Happens when I drive it as well.
I dont recall hearing this, until recently when I changed out all wires, cap, rotor, spark plugs, belts, water pump, and oil change.
Note I have only had this car for 6 weeks.
Would you give it a listen and see if you can give me any direction on how to fix?

Also I just adjusted the valves, most were fine, a couple of the Intake needed to be tightened.

[ame]https://youtu.be/cuDIvNJ26gg[/ame]