usmle world step 2 practice 4 hr exam

I took the usmle world simulated exam for step 2ck today. I am trying to take my exam by the end of november. I got half right on each of 4 blocks; so i was very consistent. my goal is to finish the test. anyway, 50% right equated to a score report of 180; just short of the passing 189 I need for this test. I MUST PASS. I would like to do well. I went up 30 points from the form 4 NBME self assessment I did just a few days ago. So I think the USMLEWORLD sim exam is right on.

I wondering which NBME exam I should take next to get a good "representation of what my score will be like " going into this exam. I have taken Form 4 twice and form2 once. What kind of experience do people have with Form 2 and Form 4?