Evans Cooling supplies a Fel-Pro housing gasket, as well as a water pump gasket. Although we've used silicone gasket sealer in past water pump/thermostat installations, we opted not to use it here. As it turned out, we didn't need it. The water pump is mounted using the studs that you previously marked. Don't over tighten them, as they are secured into the aluminum timing cover, and breaking one of those can be a time-consuming and costly repair.