Sorry, can't help you on your question, and not trying to highjack your thread, but when you find your answer and if they work for you, I have several sets of rear springs up for sale.
One set of '99 rear springs, removed about two years ago.
One set of OME 891s, used for a bit more of a year. I think I still have the 10mm spacers I used with them as well. I upgraded to 861s due to my rear bumper.