If everything else is done right, you shouldn't need the sealant. As a last resort, it works.
If it DOESN'T work, you may have an abused head (they typically leak at the top, when they leak).
Also, there is a possibility that the front and rear may have slightly different gaps, so measure carefully and use the closest thickness seal for each one.
If it DOESN'T work, you may have an abused head (they typically leak at the top, when they leak).
Also, there is a possibility that the front and rear may have slightly different gaps, so measure carefully and use the closest thickness seal for each one.