Which Rear Spring Do I Have? Options

[Mathman]

I have been feeling like my rear springs might be worn out, so I decided to buy some 100lb. springs. It should be noted that I am VERY much a newbie when it comes to the suspension system. In addition, let it be known that I am not currently into AX or any other racing applications.

That being said, I felt like the rear ride height was exceptionally low for my tastes. When I went to remove my springs, I discovered that I have the yellow Bilstein shocks with the six grooves and the little circlip to hold the bottom plate. My circlips were on the bottom groove.

So, I took off my spring, and compared it to my new 100lb. spring. My old spring is probably a good 3" longer than the new one. That seemed weird to me, so I decided to do a little more research.

I have always been told that you can't really change the rear ride height, but then I read some stuff that indicated you COULD change the ride height if you had the Bilsteins. So, I decided to move the circlip to the fourth groove (from the bottom) and install the old springs. After driving it around a bit, I like the ride height a lot more.

My questions are as follows:

1. Did I do anything wrong?

2. Should I use the new 100lb. springs or keep the old springs?

3. There are no markings on the old springs. I put a weight on both old and new springs, and they seemed to compress the same distance, but why would there be such a height difference? Any other way of telling whether my old springs are sprung?