Michael, the only need for a different headgasket that I know of is with the Turbo engines which sometimes blow the stock gasket, especially if the boost is raised. Sometimes the stock gasket is replaced by a steel ring reinforced gasket ("Fire ring") or a groove is machined into the head and block surrounding the cylinder, then a metal wire is compressed into that groove. I think that this defeats a "safety valve" which the stock headgasket provides when it fails. cheaper to replace the gasket than the pistons or rods if they should fail! No need to change anything on our normally aspirated engines, just make sure that the two surfaces are perfectly flat, not warped or gouged, and the stock head gasket will work fine. Good luck, Bob Blackwell.
