I own a 1990 300 SEL. The manuals are OK for the engine but there is no data on the trans or rearend. Where can I get technical specification and overhaul data for W126's as well as parts? Part of my interest is maintenance but the other is in conversion and parts cross-over. For example, I am very interested in an overdrive setup for the car. One approach I am considering as an option is to run a lower readend gear but have no data on what ratio's are available or what speedo gears I would have to install to keep that rteading correctly. In addition I am interested in being able to start the car out in first gear vice second but without having to maunally put the shifter in the "2" position at a stop. This would give me a true four speed with drive actually serving as an overdrive and I would not have to make the modifcations to the car normally associated with installing a different transmisson or rearend. I appeciate any help you could offer.

Thanks,
Motor Head