To be honest, I think that you will find the problem lays with the shocks rather than the springs. If the ride height is settling etc, then probably the springs, but if its handling related then I'd be looking at the shocks first, particularly the rear shocks on a D2 as they need to work very hard.
Its also worth getting under and checking all of the suspension bushes, the sway bar D-bushes (chassis mounts), lateral play in the watts linkage and the sway bar links haven't snapped which they can do.

