Top Law Schools

I'm aware that most top schools average LSAT's but do they follow this policy even when the score difference is 8 points? Is it worth the effort to send an addendum with my application explaining why I feel the latter is more representative of my logical ability?

For many schools, you will need to send an addendum explaining the score gap.

As for averaging, some schools do; most take the highest score; a few "take all scores into consideration."