Quote Originally Posted by lmcclain
I'm revitalizing my '95 540i 6-speed (I'm the orig owner) and am considering the diff gear change. Reading posts on the subject, it seems that most people just swap complete diffs, right? My car would have a 2.81 diff and I'm planning to follow the recommendation to go to a 3.15. I believe later E34 540i's with auto transmissions had 3.15 diffs, right? Are these diffs directly interchangable? Is there a better way to go?
Call Jim Blandton and have him make a chart for the different ratios. That is what I did. I cant remember what i went with off hand but the charts showed me the low end acceleration and the highway cruising RPMs. Very helpfull.

Sorry but i dont have his number handy at work either. A lot of help i am!