440 source has a permanent valley pan, it stays on there. Then you use the paper type intake gaskets for the manifold. Only problem here is, the valley cover edge sits below the cyl head. So you can remove the intake, but to access the lifters you have to pull at least 1 head! There may be another type I don't know about. I think Moroso, Mancini, Mopar, and others may have them too. Also, stage VI heads use the stock valley pan with the manifold port area cut off. Then a spacer goes over that, and you use the paper gaskets. Then the spacer can be removed, and the valley cover.
