Looks like you've reached your ceiling for your third party FL's, so I wouldn't recommend taking any more Kaplan exams. Remember that Kaplan is a third party resource, which always needs to be taken with a grain of salt. You should use your Kaplan FL's mainly to practice timing rather than reviewing thoroughly. In my case, I took Altius FL's and averaged around 515, but on AAMC FL's I averaged around 520, which was the score I ended up getting on the actual test. Save your energy and worries for AAMC FL's, and move on from Kaplan FL's.