sagging shocks (!)

["Grant Lenahan" <glenahan@notes.cc.bellcore.com>]

>>The rear end on my 86 4KCSQ has started 
>>to sag ever so slightly. Is this due to
>>the shocks or the springs? I know, it probably could be either,

Absolutely not.  Shocks only damp motions - they do not support
weight (except for high pressure gas units, which yours were not).
Basically they resist ALL motion in BOTH directions, and thus
reduce bouncing.  Technically the "damp" oscillations, thus their
alternate name of "dampers".

If its sagging, its the springs (or that block of granite you have in the 
trunk).

On the other hand, dead shocks can cause stressing of a spring, which 
will then sag.  While its apart, replace both.

Grant