I recently got my Cobra and will need to get the front wheels balanced. Olthoff's site has a video on the knock offs and he says you'll hear a definite change in pitch when it's tight, using a lead hammer. I wonder if a plastic dead blow hammer will give you the same clue that it's tight
BTW, Dennis really bangs away when he's tightening the spinner in that video... 350 ft/lbs sounds reasonable.