Its only because the axle is offset to the right but I'm still not sure what to do about the spring setup.
In effect Roughtrax have it listed wrong on their website claiming 775mm when its a tad over 790mm as per Pedders own website. At the moment I don't even have the spare wheel underneath so I guess its how much the heavy duty springs will compress with say 50kg of bits onboard. It would actually make more sense to order a 2" lift on standard spring rate than fit Standard height but heavy duty, although I'm thinking of sending them back and just getting full standard set onboard.
I did briefly consider just throwing a 100 series one in there to see how it looked. However the old setup had dropped so much I could barely stand on the rear tyre to reach the roof rack so my axle must have been off the other way to begin with!