Heat Shield Placement?

I put them under the gaskets, as the soft surface of the gasket is intended to seal against flat metal, while the textured surface of the gasket is intended to seal against the manifold. I don't know about originally, but I was dubious about using the heat shield as a gasket by itself, after being flattened so many times. It would probably work with a good sealer like Hylomar AF. I think by 67 the heat shield was on the driver side only.