What's That Ticking?

I think I'd be pulling the valve covers, but ya know what, cruise out and get the stethoscope, take the needle off, and lay the horn on each valve cover, move it around, I think it will tell all, and if the noise is lower, it'll sure help .
I think it's a rocker, pretty fast as mentioned, jmo
https://www.harborfreight.com/mechanics-stethoscope-63691.html
Great vids .