Will be installing a set of PSS10's tomorrow and am thing about dropping the car about one inch to an inch and a half. Do not want to go too low because of a fear of scraping the nose on every driveway.

 

I recently got my 996tt and it came with PSS9.. So that being said I don't have experience with "stock suspension".. I'm not sure what the max drop from sock is but mine are max low setting and I am still at 25.5 - 25.75 inches ground to wheel well..

I'm not complaining as I am satisfied with my current ride height but I do wish I had more shock travel.. I assume you have already pulled up the different posts about Bilsteins..