I see some cars basically rocking there street stance at the track (dumped), while others are about equal height to the front of their cars after it's raised for bigger slicks. Some even go as far as having the *** end a good few inches higher than the front. What seems to work best assuming you have a fairly stiff rear drag spring? Do longer wheel base car setup differently like tegs and 4drs over CRX's and hatches?

 

You want the back end a little higher so that you don't lift the nose and catch air under it at speed - it'll act like a scoop, slowing the car down. Lower's better but lifting it to normal height is cheaper, haha... you have to experiment and see how much you transfer weight to the rear to get the height right.

Longer wheelbase will transfer weight less easily, so you can get away with less height in the rear.

Someone correct me if I'm wrong, this is how I see it