It really doesnt matter what score you must get to pass the exam. Some say NCLEX is easier compared to Kaplan or the other way around. There are also people getting around 70-85 (over 100 items) but...
I only used Saunder's as my reference book. I read the book cover to cover and I passed with it. But it really depends on you, if you think you can easily understand its content then don't force...