Gasket or no Gasket on Hemi??

With factory Exhuast Manifolds, should I not be running gaskets (manifold to head) as I cant seem to stop leaks with gaskets?

I was under the impresion none of them had gaskets from the factory.

I have used High heat silicon, with no gasket, and it holds very well. Admittedly I haven't tried it on a hemi though.

Just have the manifolds machined flat and you wont need any gaskets or goop.