I used the 2018 step 3 mean 226 and SD 15 from USMLE guideline interpretation, my 230 score in NBME correlates to 3 SD which is (186) 3 digit score = fail, I took NBME 4 after 3 weeks and I got 330 which 2 sd and correlates( 201) 3 digit score= pass, all of this not official correlation it's just analysis of the information. still ccs portion not calculated.
hope this helps