This is your where you get to figure it out on your own and grow as a driver/crew chief. It sounds like you aren't out to lunch. Make one change a little farther than you normally would when you know your going to be off on the setup and note if it makes you better or worse.

DO your homework, write it down before you get to the track and every time you make an adjustment what it does for you. Summarize at the end of the night. In the long run you will be the better for it, and people will be asking you what to do. Asking on a message board is like asking the best way to train your hunting dog in three sentences or less.