Sorry, my last post does appear that I am advocating using a AAMC conversion scale for a PR test.
What I was attempting to rely was that the AAMC tests are more predictive tests to the real thing than the PR diag. Therefore, a 28 on their test is an eight I believe. I know some tests are harder than others but I do not worry about a hard or easy PR test. I worry about those AAMC tests. So, I would take more emphasis on what those tests tell me and not worry about my PR score. I use all those (PR, EK, Kaplan) for mere practice. Try to get my timing and just plain reading those kinds of passages. I think the EK Verbal is better than PR myself and seem to closest match the AAMC style.
No style is better than an AAMC style at predciting an AAMC test!