Which side of the exhaust manifold gasket (Honda 18115-P2A-003) fits against the surface of the head? Does it matter which way it goes on? For the 4 exhaust ports, one side of the gasket has slightly raised (convex) oval ridges and the other side is slightly depressed (concave). The old one is flattened so I can't tell how it went on. Thanks.

 

After looking more carefully at my old gasket, the original installed by Honda, the indented side was against the head.