Max. spring rate for Yellow Longstroke Koni's?

[Spitfire]

Cheers lads,

well, the title says pretty much everything I might be lucky enough to get a full set of Yellow Longstroke Konis (as allways hugemegabig thanks to SekiguchiUeno!!!! ) for my crappy 86 and also (again, thanks to Stano ) a contact on a company which makes custom springs (very cheaply). So, with that kind of combination lying in front of me, I would like to ask people who have the experience to tell me how stiff can the Konis go.
I was told that Mux here was driving with 6kg/mm springs, which would be awesome because thats exactly where Im aming