My new truck (suburban K20 -77) rides so rough it´s hardly driveable. the PO installed superlift 6" liftsprings in the front and blocks in the back. It´s also got superlift shocks. The ride's so rough that if you go over a small bump in the road the truck almost bounces off track. Is this normal for superlift springs? I´ve heard they're really stiff but this is extreme. Can it be that the shocks are too tall so they are compressed all the time? It looks like they are really tall for the liftheight. Do you guys think I can make it a bit nicer just by replacing the shocks or are the springs the real problem?