I made a video to demonstrate the noise:
https://www.youtube.com/watch?v=qZXX...ature=youtu.be

Setup:
Stock block
HKS 264 cams
OEM cam gears
Fresh timing belt and tensioner
OEM lifters (cleaned and bled; none were collapsed
RC 1000cc injectors
E85
stock turbo/manifold
~350whp at ~24psi
Rotella T6 5w/40

I can't really link any specific event to when it started ticking. It has been ticking like this for quite some time. It does not tick when cold and does not seem to be related to load or follow RPM accel like rod knock does. I have bled the lifters and checked to see that none were collapsed. No rocker arms were off or anything. I've probed around with a stethoscope and can't pinpoint exactly where the noise is coming from other than it definitely seems to be coming from the left side of the head.

Anyone have any thoughts or input?
Thank you for your time!