I think they had ratios up in the high 3's.... like 3:92 s or :78's..
so don't expect low cruisin' RPMs.
The ratio is stamped in the lower , right casing on the diff. ... might want to take a peak there for exact specs.
Also, check that someone did not go w/low profile tires, as this makes it worse
The Euro "R" tires on the older Benzs were 80 profile, which is much taller than standard US specs.....