Their website doesn't say you can't...
I would contact them before committing. http://bbbcycling.com/bike-parts/headset-parts/BHP-21
You'd have to remove the star fangled nut / bung that's already in the steerer. It works exactly like an old school quill stem, with a wedge that is pulled up a chamfer. Can't imagine it would do any more damage than a bung / star fangled nut.
But then I'm an IT Manager, not a an engineer...
Not so much a six pack as a barrel!
1959 Carlton Continental 1982 Carlton Professional
1987 Peugeot Perthus Pro 753 1995 Colnago Superissimo
1995? Vernon Barker MTB 1993 Colnago MTB
2005 Colnago CT2 1978 Carlton Clubman