Hmmm, you'd think if one spring was sagging they both would. Adjustable coils may help with that. You can get true coilovers that have the bottom and top of the spring attached to the shock [like a strut] or the ones I have that have the top of the spring going into the original spring pocket. I know a couple others on this site have them, I think Quick68bird has them on his car and by the look of the pics he has the stance lowered a bit, looks nice. You should weigh the car at the front wheels and the rear wheels, with and without driver and passenger then use that info to get the spring rate you need. I got a set of QA1 coilovers part number GS401-10450A from Amazon. They shipped to Pender Island for free and cost me less than half what they would have from anyone else. You may not need the 450 pound springs. Do some asking around and check the weight of your car. I went to a waste company that weighs the truck before and after picking up yard waste, he brought the scales to my place and weighed the car while we had a case of beer. I got the numbers for empty car, driver only and driver and passenger at all four wheels.