I think Willamette is referring to the NBME basic science comprehensive exam. It's a 175 question test. Our class took this in the middle of March. A 63 is considering passing and is equivalent to a STEP 1 score of 183. The mean on the NBME basic science comprehensive is a 70 with a standard deviation of 8. A 70 on this exam correlates to a 200 on step 1, a 78 = 220, etc....
By the way.. a 63 on the exam does NOT correlate to a 63%, nor does a 70 correlate to a 70% according to the score interpretation guide...