Here's a link to the statistics for the top law schools:
http://www.top-law-schools.com/rankings.html
As you can tell, the median GPA drop is significant when going from 3 (Stanford) to 4 (Columbia) but the average LSATs stay about the same for the top 10 schools (excepting Yale and Harvard of course). The exception is Boalt, whose 25 percentile LSAT is much lower than the other T-10s.