I just spent an hour trying to find the length of the springs. I going to use the adjustable spring perches, but when I look for springs they go from 7" to 12" in length. What length fits these shocks and our cars?

It depends on the # of the springs you are going to use. It depends on your application. Some are only availlable in certain lenght and diameter. Call the guys at Ground Control and they will set you up with a package or at least info. For my my Konis shocks I still had to have two more groves machined in them to get the car to sit lower with 10" 200# springs on their perches.

The ten inch springs have more choices for lower weights (80-225lbs) if I go with smaller lengths my choices are less.