Are your springs balanced? That's the true first step, but I sort of left that out in only talking about oils/pistons. It's the same push/release test you use to check your oil, just without oil in shocks. With balanced springs and no oil, your car will pop back up evenly.

You can either change to a smaller piston in the rear, or go to a bigger piston up front. That all depends on if you feel the car has too much or not enough pack when driving on your track.

Once you change pistons, pick some oils to start with, and do the push/release test. Adjust your oils based on the results of this test to get the car to return to ride hide evenly.

Then try the pack test again and see if you've improved or not.

Good luck! I don't know about anybody else, but I have almost as fun tinkering with this kind of stuff as I do driving!