You are going to be just fine if you were in the 75%. You need to score below 10% on the actual exam to fail, given the approximately normal curve distribution it would take a preposterous change for you to fail. Like you find out your parent passed away en route to the exam whilst getting t-boned and hobbling up to the computer completely broken as a human. I know of no one who's PRITE to boards was >2 STD change and almost no one who's percentile moved more than 20-25%. Yes, I talk about test scores for fun and thought psychometrics was one of the best parts of a psychology undergrad.
Definitely open for anyone who is willing to post about a huge difference in their last year before boards PRITE to board exam child or adult.