To break the barrier of 170 on the LSAT really depends on the amount of time you grind for the test. The LSAT is a test that requires a different study approach than most traditional exams - meaning you can’t cram outside information like the GRE or ACT (if I was able to bring in a cheat sheet to the LSAT, I really wouldn’t know what to put on it). What the LSAT really tests is your ability to think a certain way - to analytically read through arguments or premises and make deductions about what can and must be true.
This being said, some people are more naturally suited to this line of thinking than others. But these are skills that are able to be learned. And if you are willing and have the means to really, REALLY grind for the test, you can get there.
Any score above a 160 is considered a great score, and any score above a 170 would be considered an EXCELLENT score, within the 98th percentile of all people who took the test, meaning that you were better than 98 PERCENT OF THOSE PEOPLE WHO TOOK THAT SAME EXAM. Scoring this high would land you a great chance of getting into any law school, even Ivy League. If you took a practice LSAT cold (no study or preparation) and scored 158+, you are more suited for the type of of thinking required for this test than others, and can most likely score in the mid 170s with a few months of intense effort.
Also, not everyone needs to go Ivy League to be a successful attorney. Remember that you can still get into a great law school that better suits your needs with a score lower than a 170. For example, when I started preparing, I wanted to score between 165–169, which would land me a scholarship at the schools I was considering. Through intense preparation, I met that goal.
The important thing to remember is to set a realistic goal for yourself that you can achieve with preparation, and then GRIND LIKE HELL to achieve that goal. You can do it as long as you really apply yourself and cough up some cash for quality assistance.