huckapatooey

I am having an issue with a ticking sound that seems to be much more pronounced from underneath the passenger side of the car, and only starts once the engine starts getting up to operating temperature. I have been told it may be the lifters, is here any way I can verify this without pulling the heads/special tools? I haven't really driven it since I noticed it, but I hadn't felt a loss of power and all guages have been normal. I have check engine, but only codes are for the headers and lack of rear O2 sensors. Below is a video, what do you guys think?