rear of 4000Q sags

[VFChris at aol.com]

My 86 4000Q sags in the rear.  Does anyone have any suggestions on how to fix 
this, other than buying new springs at the dealer for big bucks?  

And before you suggest a set of sport springs, I am absolutely not interested 
in lowering the car, or making it ride rougher than stock.  I live in the 
Northeast where there are lots of potholes, and otherwise poor roads.

If anyone has some suggestions or experience than can help me, please E-mail 
me personally, because I do not pay regular attention to the list.

TIA,

Chris