Because both the manifold & the head were still relatively true & UN-rusted, I used the same sealant as the factory - chassis grease in a thin film around each port. When the manifold gets hot, the grease will bake into a varnish, much like cast iron cookware. The varnish creates an effective seal. And like seasoned cast-iron cookware, it's also a non-stick coating, which allows the manifold to expand & contract without cracking. Gaskets can adhere and cause binding, which makes cracks more likely.

If the surface is too rough for grease to work, use high-temperature silicone.



Years later, I did this:

Owner caption November 2009 · Photo 65 of 434