Folks, there is a long-winded thread on MBWorld regarding the limited-slip upgrade options. It's different for various chassis, ring gear sizes, and ratios. And it isn't cheap. Keep in mind the factory clutch-type LSD's wear out, cannot be bench tested, and cost several hundred dollars to refresh the clutch packs (parts only - that doesn't include labor). If you happen to get a used one that fits your car cheap, don't get too excited until after it's installed and painting elevenses. Anyway, the other thread has more details...