rear spring question

[Nick Lawrence]

Comparing rear springs from a '91 200 20v sedan and '90 20010v wagon.  
Does anyone know if the '91 springs are as stiff or stiffer than the '90 springs?
My wagon looks a little droopy at 235k miles and I have some '91 rear springs that have not had a car on them for 5 years and about 100k before that.   I would swap them if they would hold the rear end a little higher.  TIA
Nick