I wouldn't bother. If you're old enough to be taking the LSAT, a high IQ score won't be opening any worthwhile doors for you; at a younger age you might have been able to leverage it into admission to some useful programs, but now it's only good for bragging rights. And it's not something that it's socially acceptable to brag about in most contexts. (I don't remember ever mentioning mine past high school, except on the mostly-anonymous LW surveys.)