Thanks for the input, I get it about headers. I will look at the gasket seal and make sure it is solid. I machined the header mounting surface before installation 20 years ago so I may have a chance for a tight seal. Is this appearance typical of a too lean mixture? All the valves look the same. The plugs I removed recently look like this photo and again all the plugs looked about the same. If both the plugs and the valves indicate too lean mixture I will rejet the carburetor. Thanks for the help
