Does anyone have any idea where this "knocking"/"clunking" noise is coming from?

It usually happened on cold start then goes away a little when its warm. Doesn't fully go away but its less loud.

It does have a skunk2 valve train and AM intake. That is all the aftermarket stuff done to engine.

Valves adjustment performed less than 200 miles in.

 

 

Hard to say when the valve train isn't stock. Doesn't seem to be normal, but I can't find anyone else with an open hood idle like yours.

 

What is the reason for downgrading the valve train?

 

previous owner

 

any ideas what the source could be from?