Have you polybushed the rear blades, the bush with the metal rod going through the middle?

This is mine before i removed the bush



This is mine polybushed



If your on standard bushes the setting is only critical as the rod is bonded to the rubber and it is so that the twisting effect does not tear the bush, if you have polybushed this then the rod rotates freely so it does no matter what its position is

You could easily take an angle off the photo of the standard bush i have attached

I love this pic of my rear subby before i installed it