Mercedes Benz repair: springs, rear shock, 300sd

Question
1978 280SE,best way to replace coil springs,shocks, is there a better spring for the 116ch, and what is the hight,rate of twist and coil diam ?

Answer
These threads cover all needed information.

126 rear shock change
http://www.mercedesshop.com/shopforum/showthread.php?p=1031835#post1031835

Rear sub frame Bushings W126 1985 300SD DIY
http://mercedesshop.com/shopforum/showthread.php?p=796976#post796976

Trailing Arm Bushing W126 1985 300SD DIY
http://www.mercedesshop.com/shopforum/showthread.php?t=111052

Anyone ever broke a rear subframe bushing bolt?
http://mercedesshop.com/shopforum/showthread.php?p=461406#post461406

Steering squirrelly W126
http://www.mercedesshop.com/shopforum/showthread.php?p=778649#post778649

W126 subframe mount clarification needed
http://mercedesshop.com/shopforum/showthread.php?p=370569#post370569

W126 Ride quality
http://mercedesshop.com/shopforum/showthread.php?p=543139#post543139

300TD REAR suspension rebuild
http://www.mercedesshop.com/shopforum/showthread.php?p=373288#post373288

300TD suspension rebuild progress
http://mercedesshop.com/shopforum/showthread.php?p=370364#post370364