200tqa rear end

[e2e]

Hi all
Myself and others have saggy bums on our avants. I am wading through the
mire of fixing the problem. My car is about 25mm down in the bum, worse on
the right. It appears that standard height springs don't exist.
 My shocks are red Koni at the rear and yellow Koni up front. Just how much
difference is there between reds and yellows?
In my hunting around for springs I have discovered that Mitzi Sigma fwd
FRONT springs look to be nearly identical. Has anyone out there in cyber
land taken off a set of old springs that they could measure up internal
diameters top and bottom, wire size and some idea of what the free length
should be. Mine are still on the car, of course, so accurate measurement is
a problem. Now if these Mitzy springs are compatible then there are lots of
aftermarket springs available of various lengths.
I am however tempted to strip out my rear shocks and get them fitted with
adjustable height spring seats, in which case maybe I should change the seat
size and go for other springs completely....BTDT's please.
While the shocks are stripped should they be re-valved up to yellow specks
or can they be merely adjusted up to match my yellow fronts?
-- 
Sam Clarkson 
1990 200tqa