W126 shocks on W123 - anyone tried it?
 

Front and rear - they look similar as far as mounting goes. I'm considering Bilstein Sport (B8) shocks. I figure the increased damping should work well on a lighter car than intended, with stiffer springs than intended.

Anyone tried installing W126 springs on a W123? Is there a difference in expanded/collapsed height? Shock mounts?

NOT MUCH HELP, BUT:
 

Do a cross-reference @ NAPA, and/or AutoZone, or another Import Auto Parts store tomorrow.

I did the free replacement deal through AutoZone on my W126's Bilsteins in the '90s. -Best deal going! 100% FREE replacement when just one shock starts leaking oil - take 'em ALL back with your receipt for a FREE SET!

A cross reference will not work, since they do not cross reference. Two different part numbers, and the mouth breathers at auto parts stores become useless if the numbers don't match.

I will just buy a cheap or used shock if nobody here has any experience, but I hope someone might.

By tomorrow afternoon - I'm relatively certain that any number of guys here will give definitive answers to your original Q.

I have only investigated rear shocks. Technically they are different part numbers for the original equipment.

In the aftermarket: Bilstein lists different part numbers for w123 and w126, however Bilstein prides itself (i.e., claims) that it valves shocks to each individual application. So it would make sense they have different shocks for each.

I found that other aftermarket suppliers I looked at (Koni, KYB and Monroe) list the same part number for certain applications on both.

That says they should fit. It does not guarantee you will get the performance characteristics you are looking for....

I used a pair of rear shocks out of a w126 in a w123 car. Worked fine, don't know about the fronts.

Well on further research, KYB brand lists the same part number for front shocks for both W123 and W126. Promising! Also, Monroe has different shocks for the two cars, with the following compressed/expanded specs.

W123: 15.125" / 20.000" (stroke: 4.875")

W126: 13.625" / 18.375" (stroke: 4.750")

More good news! If Monroe's products are any indication of what to expect from Bilstein, W126 front shocks have a 50% travel height 1 9/16" lower than W123 shocks. So now I have a target ride height!

That question answered, I'd still like to know of any first hand experience running W126 shocks and their damping characteristics on the smaller car.

That Monroe stuff is absolute junk. I would never in a million years put monroe stuff on my car. I think I would rather ride on 30 year old broken Bilsteins than buy new Monroe's.

Thanks for the concern but if you look back I never mentioned using Monroe shocks. I only used their specifications for comparison purposes.

My Dad used those monroes a couple times for his courier van. Both pair finished in less than 3 months. He never used them again. Granted that courier work is hard on them, but still. I am sure some of these forum members are still riding on 30 year old bilsteins, I know one of ours still has them.

Billsteins from a W126 worked just fine in my W123 wagon.

Sweet! What model did you go with? They offer B8 "Sprint" shocks for 126 cars and from what I can glean they are lowered versions of B6 "Sport" shocks.

What are you building? Sounds like a lower ride height is what your looking to do.

nice... will it run on biodiesel?