Coat the inside with Caswell's to make it impervious to any fuel. This small step will ensure you happiness down the road. Don't over tighten pump flange bolts or gas cap bolts as you run the risk of cracking the area that holds the nuts in place. Pump mount surfaces can be slightly deformed so a thin bead of gasoline impervious silicone will help seal best. Put the sealant on, put the pump assembly in and tighten and then let sit for 24hrs to be sure the silicone is cured.