The Moroso rubber gaskets work okay when captured between two flat machined surfaces. I wouldn't use them for any other application. The Moroso gaskets split apart almost instantly when used with cast valve covers that have the step in the wrong spot. The cast valve covers shear the rubber just like a big knife.

Picking the correct gasket for an application requires some knowledge. When you are sealing two flat machined surfaces a thin gasket like the Superformance pink works great. When you have cast iron heads and flimsy sheet metal valve covers then you need something super compliant with lots of give so it can fill in the voids.