AS far as valve cover gaskets, I go contrary to the recommended practice and securely fasten the gasket to the head with # 2 Permatex.
This is better for being able to remove the VCs and not catch the gasket on rockers, disrupting the seal.

Works to your advantage on Iron heads as they now create a higher oil "wall"
as on newer Al. heads.
I smear the #2 on the inside face of the gasket where it's exposed to oil and spray a dry lube to the contact surface of the VC.

This has worked well for me on two different engines; one 906 headed and one Super Victor.

My 2 cents...Joe