Google the question and pay attention to thread type....dry/lubed/rusted and material type. Usually SS bolts that are mated to cast aluminum housings have thread depths that compensate for the softness of the alum. castings.
If I read you right you are just securing the water jacket cover which sees no more than15 psi max water pressure. I use an aircraft sealant (I get at the mom and pop auto parts store, not chain) on both sides of the gasket since the aluminum casting is pitted from corrosion and not like the "dry" gaskets used on new production equipment.
The 3 step X pattern is what I use (same thing used on sealing engine head gaskets....different glue however....Copper Coat there, made for head gasket sealing) from the center make a short X and keep moving on out to the ends of the cover extending the tips of the X. The last "torque" is a couple of good raps on an 8" long ½" boxed end wrench....assuming you are using 5/16 SS bolts.
