Originally posted by funfenix69
What's involved here? Is it doable? Has anyone done this kind of thing before?
Yes, with enough money.
You're probably one of a kind
Seriously, the 5-link suspension in the W140 (I think that's what it has) has more in common with the W124 than the W126. The structure of your W126 would have to be completely redone to accommodate this next generation suspension. Then the suspension would have to be tuned to be softer because a W126 doesn't weigh as much as a W140.