Low stress area, so I would JB Weld it. Cleaning the base metal is the important step. DV shows building up port floors with epoxy. He drills a few holes right through and flares it so there is a positive lock on top of the chemical bond. Sure do not want that breaking loose and heading through the intake valve. That area has no fluctuating air flows to dislodge it, just vibrations and expansion and contraction. For what is involved the epoxy will function well as long as the base metal is clean. When you clean it, be ready to apply the epoxy right away. Aluminium gets surface oxidation virtually immediately that restricts adhesion. Again, a low stress area so not as much a problem.
