we will probably put longer shackles on the back or go with a shorter shock... the shocks are behaving like bumpstops in the back.
You'll be best to go with a shackle. From the pics, it looks like the shackle is completely angled out, whereas the springs isn't flat from being convex. In comparison, your front springs look great for the movement. The shackle angles out whereas the spring flattens, then concaves. Perfect for it's function.
As for the rear shocks, isn't there enough room to do an angled inward setup, similar for a Sami?
You also forgot to add, that the front sway bar was still attached. Take a look at those bushings in action.....