Couple things:
- 'Scuttle Shake' isn't unique to Healeys; Mustang convertibles, at least the early ones, had it as well (my dad was a factory rep for Ford when the 'Stang first came out, and he said it was a common complaint from customers; our '65 convertible had it bad). Convertibles don't have the structural rigidity of coupes or sedans, and are usually heavier due to additional bolstering required in the chassis, which may or may not eliminate the shake.
- My BN2 had it, until I got a new set of (5) MCS wheels and Vredestein tires (no shaving required). Now, it's smooth up to 75MPH (I have no reason to go any faster in that car, and the crankshafts are known to fracture above 4,500RPM).
- Shaving tires will likely void the tires' warranties, if that matters to anybody.
Ok, three things.