https://realgaskets.com/product/valve-cover-gaskets-29/

orange reinforced silicone

The more recent black "rubber" valve cover gaskets suck especially the fel pro ones. I wish they still had the old orange rubber ones
The black fel pros are too hard and don't have any "give"
Usually with valve cover gaskets I go snug plus 1/4 turn

my old mind and cobwebs are at it again.
way back somewhere in time, i remember a statement saying the bolt holes on the heads were NOT at a 90 degree angle to the sealing surface.

my old mind and cobwebs are at it again.
way back somewhere in time, i remember a statement saying the bolt holes on the heads were NOT at a 90 degree angle to the sealing surface.
has anyone else heard that ?
i can't remember if that was brought up during a cast valve cover discussion or a gasket sealing discussion.
regardless, if the tin cover is deforming, sealing is going to go away, and more torque applied is going to make it worse.
it is harder to get an "as cast" surface to seal than it is to seal a machined surface.

Mopar sells a gasket like the Cometics that sniper posted. They are the cats meow and are reusable many, many times. I've been using the same set for over twenty years on my race cars and now my truck.