I am going to be replacing my rear shocks with OEM Bilsteins. The question I have is which would be best for my '80 W116, standard or heavy duty. I tried looking up the part number for the HD shocks, but it came up as not being in the data base. I got the part number for the HD shocks from the benzbin. With the weight of my W116, would a heavy duty shock be best or would it give to harsh of a ride. Not that I want my car to float like a Caddy, but I don't want to have a bone jarring ride either. Also if someone to clearify the removing and replace of the rear shocks. I looked at the manual and it gives the impression that you can remove the shocks with the car on the ground. It says to remove the back seat, unbolt the top bolt through the access hole. Then remove the 2 lower bolts that attach it to the control arm, and just remove it in a downward direction. The reason I am questioning this is because there wouldn't be any room to pull the whole shock out. Maybe the meant to say after removing the top bolt, to raise the vehicle, then remove the 2 lower bolts.
Any past experience from anyone would be greatly appreciated.

By the way nice looking car. I must commend you on the nice condition and also noticed how clean your front wheels are. I think the rear suspension needs to be unloaded in order to get the shocks out of there. I would also recommend heavy duty shocks. The handling will be a little better. The ride will not be too harsh unless you put some harder compound, wider tires on the car.

on a 300D
 

My Hayes manual does not say to lift the rear of the car off the ground, but my Chilton's Manual does, so go figure. I would think you would have to remove the wheel and lift the car up..I always did on my Chevys...

The more I think about it, you probably remove the top bolts with the car on the ground, then jack the car up. With the car on the ground there isn't enough ground clearance to pull out a fully extended shock absorber. Of course when dealing with compressed suspension components, guessing on what to do can be dangerous, so that's why I started this post.

Use the MB jack for proper clearance
 

I have changed the rear shocks on my w123 using the stock mb jack at full height. They drop right out. I never took the wheel off.

I think the standard bilstiens would be fine for your car. That is likely what you have been driving on, and what the car originally came with. Standard doesn't mean soft, it just means its what the car came with. The HDs will firm up the ride a lot more.