CJ wrote: "...I have to agree with KEN C. The 1986-1994 300E came with the 3.07:1 rear end, according to the MBZ Specification Book I have by Frank Barrtt. ..."
CJ, I'm reluctant to disagree with someone who says that they agree with me, but let me point out that, whereas the table on pg. 139 (assuming you've got the edition with the yellow SLK on the cover) states 3.07, that table has some copywriting errors (note the 117 hp for the engine???). Instead, read the passage just above that table (right column), which states that "'86 through 90 cars started in 2nd gear ... (2.87:1 vs the previous 3.27:1)." There is no mention of any car having 3.07:1, contradicting the table.
But thanks for agreeing with me :-).