Agree with others, talk to the coaches or another counselor. Top private schools sich as this will have a counselor available to talk with, even though his counselor left.
For non-top D1 highly recruited athletes they often seem to have to get closer to the actual max rigor offered at the school, and have a higher class rank, but this is still very sport-and school dependent.
Though it seems like 8 is about the max at your school, this may not be true. I definitely don’t recommend guessing given the resources you have at your disposal at a top HS. At the main competitive 2 privates in our region, 8 total doesn’t typically put one in the top 10% of rigor, though it could. Which APs chosen matters more for admissions than the total number (the schools offer almost 20).