I know Quaife and OS Giken have LSD's pre-made for the E55, part number QDF7V. I know the mercedes final drives share the same bolt pattern as far as I have been able to reasearch.

I dont know the differences between the slk/clk v6 and v8 pumpkins as far as physcial dimensions but I would imagine it would be worth looking into considering the differential is only 950 and readily available.

Thoughts?