I'm in almost the same position - slightly lower GPA (3.73, below most 50% percentiles where I'm looking) with a 171 June LSAT. Debating retaking in August (which would be my third time).
I think you should be able to top a 171 if you're comfortably PT'ing in the high 170's. But it's hard to predict how difficult this test will be compared to PT 89 for example.