It's not something I would worry about.carlengerer said:i thought one of the reasons for adjustable cam pulleys was the weight.
I say that as, chaps with the lightweight engine pulley sets say that they've not noticed any difference with them.
So, with the cam sprockets being so small, and the stock ones not being that heavy anyway, any weight loss would be indistinguishable.
The only reason why I'd buy adjustable cam sprockets, is for the adjustability ! ;-)