Aluminum is dodgy on a good day...:wink::ashamed: The scenarios I've put myself through include tearing the threads out of the aluminum, breaking the fastener off in the aluminum, heating up the aluminum until it flashed and melted,:frown::ashamed: and especially frustrating, not having enough room left over in the casting to insert a heli-coil.:frown: Yes, I've got several worn out "Been there, done that to myself" T-shirts. My classic fixes involve stainless fasteners and marine-grade Never-seize.