The springs fitted to cars with self-leveling rear suspension are softer and longer travel to allow the Boge-Nivomats movement to build up pressure to get the ride height back to about 30mm below normal when fully loaded.
To my mind that's not self-leveling as it should return the car to the correct ride height but apparently that's the spec of them, can't remember where i found it though.
Anyway, with standard shocks, they end up overworked because of the extra travel and softness of the springs so they need the standard springs to make sure they last and work correctly. Just replacing them on mine increased the ride height about 30mm on the back end because the old stuff was so tired! Improved the road manners and noise levels too, the suspension, back axle, propshaft etc is now at the correct height so no weird UJ angles within the prop and so on.
Ebay was where i found my springs and shocks, have a look and if you can't find them let me know and i'll go through my purchase history to see if i can find them.
