Valvetrain noise?

[FLGN]

I have some valvetrain noise that sounds like a bad lifter or a cam lobe. How should I go about diagnosing this noise. Sometimes quieter than other but seems to be always present. It's a flat tappet 210/205 w/ GM lifters. Thanks

 

[Boost231]

Start my pulling the valve covers. Once ytou do that start the car and see what the lifters are doing. Once you do that go from there

 

[FLGN]

I will try to get a Harbor Freight stethoscope this week so I can maybe pull the correct valve cover. I will also check the cam sensor for noise as mentioned before.