I'm going to be pulling the springs and shocks on my 90 shortly and replacing them. They may be 7-8 years old but probably don't have 30k on them as much of that time was spent building the truck. They started life on my old D1 as for a three inch Rovertym lift. On a 90, I think they are too still/tall so its time for them to be replaced. They would be much better suited to the heavier Discovery or 110/130 than a 90.
If there is interest here, I'll be happy to help rurr/ship them. Probably be available within a month.