I was looking under my car (94 vert) today and noticed that the rear subframe has a crack under the left rear diff bushings. There's also a smaller crack (slightly offset from the outside) in the reenforced section on the inside. From what I understand this is not very common but I've seen a few other posts where it has cracked in the same area on Z's. I've explored my options (welding, used, new) but I'm a little concerned about the cause. Could it just be fatique or is there something with the setup of my car that might have caused it (eibach springs, tokico adj shocks, spl upper arms and spl toe rods on rear)? I've see posts in the pasts indicating that the eibach springs don't have a high enough spring rate to keep the shock from hitting the bump stops which seems to hold true for my car as well when on a bad section of road, not sure if that could be partial cause? Just looking for some ideas on recommended replacements and whether I'm at risk of encountering the same issue shortly after replacement with my current setup.