[67CamaroRS/SS]

Hey everyone. I drive a 67 hardtop. It's a mono leaf, but the springs were custom jobs. They are made out of graphite. I notice the rear sitting a little lower than the front. I know the springs are good. They aren't that old. Another issue I am having is I installed four new Edelbrock IAS shocks and when I first installed them the car rode pretty good, but now that they have about 200 miles on them the ride is starting to get rough again. Any suggestions with either issue? The springs are really beafy IMO, for mono leaf. They are almost 1 1/2" thick. I know the spring is what supports the vehicle weight and controls ride height, but is there anything else I can check? Any help would be greatly appreciated. Thanks.