James,
I'm guessing- you are talking about the SD?????????????
Yes, guide rod mounts are common on W126 and much easier to install than on a W123. If you are going to do more than guide mounts and rear subframe mounts, I suggest careful inspection. Parts are cheap, but it takes a fair amount of labor to install.
If you re place all the rubber, upper and lower ball joints it will ride like a new car....
__________________
Michael McGuire
83 300d
01 vw A4 TDI
66 Chevy Corsa
68 GMC V6 w/oD
86 300E