Here this will help too.
https://www.gmforum.com/t185453/

Front valve cover gasket was easy. The back one needs to be done when you have everything apart to make that one not so hard to do. Get your new grommets and valve cover gaskets and go to town. Best of luck and let us know what happens and get your torque right on them valve covers because they are made of fiberglass and will break if you tighten them down to much and they will leak if not torqued to specs. Be sure to clean up cover grooves and the metal on your engine for a nice clean seal for your gaskets to slip into.

I'm finally getting my head around this project and have a parts list ready to go. 3 questions though, do I have to buy all new rocker arm/valve cover (whatever they're called) bolts? What and where are the grommets? I hear a lot of people using "Brake Kleen," what does that do?

Just took the supercharger off. Going to have to get a new SC gasket because it fell apart. But all went well, now just to get a few things out of the way for the valve cover gaskets...put it all back together and it'* done. Thanks for your help, it helped make things go a lot smoother.

Glad to help out and may the force be with you.