Hey all - On my 2004 Yukon 4x4 I am replacing the rear springs/nivomats with a set of Z71 springs I picked up. I found that there are different versions or sizes of the 5100 Bilstein shocks, so how can I tell which specific one I need to work with the Z71 springs? For the front, the PO says it has a leveling kit, so how can I tell what size 5100's I need for that as well?