The Mopar XHD springs are one of the most mis-understood parts on the market. Many, many people pick these up expecting them to increase ride height. The simple fact of the matter is that they are not designed to increase height, but to simply restore the original ride height. The benefit of the XHD spring design over a standard spring is that they have an increased rate for torque control. This is why they came on 440 and Hemi cars. What many people seem to forget is that aside from the AAR/TA versions, almost all E bodies did not sit with a rake to them. Yet, after restoring a car back to stock, most are disatisfied with the stance. So they break out the credit card and buy a new set of XHD springs thinking they would lift the rear. Unfortunatly, mymopar experienced what most find out and are unhappy about; their stance is no different than before.
Personally, I'd rather leave the rear at the stock height and lower the nose or use different apsect ratio tires, but that is just my preference. Adding arch, or camber, to a spring reduces its ability to resist twisting, or roll, so you are reducing its handling capabilities by arching the spring. However, most of us don't drive our cars at a level that this change is blatently obvious. Mopar designed their springs to sit with very little to no arch at all. It is even acceptable to run them with some reversed arch under compression.
I can say that after having installed four set in my cars and my brothers cars, and having sold a dozen sets in my previous business, all with the expectation outlined above, no one has been disatisfied. However, mistakes can happen and mymopars experience outlined above is truly unfortunate. However, I wouldn't attribute his situation to a poor spring design or the fact that the springs are made in Mexico or Canada.
If anything comes of this post, it is this, and the more people that know this the better; XHD SPRINGS RESTORE ORIGINAL RIDE HEIGHT, THEY DO NOT RAISE IT!!
