Help w/ a couple 4KCSQ problems

[Mark Hilbush <73441.73@CompuServe.COM>]

My 87 4KCSQ is blessing me with a couple problems that I can't figure out. 
Probably knew I test drove that 86 Mercedes 190E 16V today...  Anyone out there
who can point me in the right direction.

1. When I disengage the clutch, such as when coming up to a stop sign or traffic
light, the rpms drop to around 400-500 then return to normal (around 950). 
Otherwise, everything else seems to work fine.  Starts ok cold, cold idle ok,
starts ok warm, warm idle ok.  This is more an annoyance than anything, but I
don't like it.  Pleeeeeeze don't say idle stabilizer.

2. On a level surface, the right rear of my car sits about 1/2" to 3/4" lower
than the left.  RR tire (205/50-15) rubs a bit on big bumps.  Car still has oe
springs and shocks.  Could a bad shock cause this?  Checked the RR shock and
found no leaking.  Shocks are worn all around, but only the RR seems to be
sitting low.

TIA.

Mark Hilbush
Baltimore, MD
87 4KCSQ