Try swapping sides with the springs to see if that changes anything. That would decide if it's spring related, or frame/hardware related. Also, try to keep springs in pairs, meaning don't put one XHD spring and one Super Stock spring on the car. While you're in there, look for signs of bent or tweaked frame rails. Wrinkles, pinching or asymmetry can be signs somethings not aligned right. For what it's worth, I and many others have had NO luck with Mopar rear springs when it comes to saggy butt syndrome with these cars. From what I hear ESPO and a few others make good springs, I just have no personal experience with them.