Loose rockers? or something worse?!

Hey guys, coming home from the drags I noticed the valve train getting very loud. I just adjusted the rockers like 800 miles ago. I have the trackheat stage 1 kit and all supporting mods. Are they supposed to lossen up as such or do i have a bigger problem?

thanks
v

Here is a short video of my issue

YouTube - ‪Mustang loose rockers?!?!?‬‎