Welcome/////It shouldn't leak. There is no said gasket just the rubber ring gasket that seats around the lip of the thermostat which in turn sits in a stepped depression and surrounded by the outer flat edge of the waterpump and housing assy's. You could put a light dab of sealant in the lower stepped portion if you like. The Torque is important too as the aluminum cannot take alot so if its too tight then it could cause problems then you will need a new water pump. Blue thread locker or fresh lock-nut washers are other options as well. I/ve talked enough, hope this helps.