I drive a 84 Alfa Romeo spider, the car is ok, but front roll centre is underground ( easy to fix) but the rear is on top of the differential, not good. Tried this question at Alfa Romeo bb.not to much help,or they won't listen. I am thinking about using a torque arm rear suspension with a pan
hard rod to located the rear axle side to side
Photo upper is one Alfa Romeo spider. Mythought is the alfa (If you remove the 'T' bar locating the rear axle) is similar to a 2001 camaro,but the camaro has the torque arm suspension, and the rear axle roll centre is a lot lower. So from what I have asked and photos that you see. Is going to a torque arm rear suspension with a panhard rod ,a better idea, than the oem Alfa Romeo spider rear end?
Have you looked at a mumford link?
A watts link would be better, but a mumford tends to package better in some situations.
Here is a few copyed photos of a 2001 camaro rear suspension,look closely you can see the torque arm suspension.i have room under my Alfa Romeo spider for this add on, also I am not using a one Alfa Romeo spider transmission.i run a w/c t5 tranny from a 1998 mustang with a aluminum driveshaft 2 u joints at the tranny and at the rear axle 
Triangulated four link in the satchell configuration, if you have the room for it. It's really simple and elegant. Also a torque arm system could be pretty nice if you could relocate the third link underneath the axle like so:
https://goo.gl/images/LbKBi9
However the torque arm has some potential drawbacks. Torque is applied in a bending moment that means all of the mounts and the arm have to be really beefy. Also torque arms require a sliding element. Both of these will tend to reduce the suppleness and response of the rear suspension. You won't need a panhand bar if you kick the outside links in as they go forward, however this can introduce a lot of roll steer!
In contrast, a triangulated four link is kinematically free through simpler means and the links are only subject to tension and compression, allowing it to be lighter and more efficient.
In reply to Stefan :
Yes,,nice but $$$ thanks thuo
In reply to freetors :
I tried to post photo.no luck is it the top photo? If so that has a watts linkage and a torque arm
Almost all the Opels they sold here were torque arm rear suspension, and judging by how many tracks banned Mantas back in the day it must have handled all right.
