You can O-ring the block they also do this with drag cars. A grove is made in the cylinder block and filled with a special copper wire. The copper presses into the headgasket around the cylinders. It gives a stronger and tighter seal around the cylinders. It prevents the gasket from moving and creating leaks. had my car done also. You can also do this yourself, there are some diy sets though i should let a machinist do this. Tapping in the copper wire is a pain to do.