I'd like to upgrade the X-Fusion on my Evo. I'd prefer an air shock. As you already know I can't just buy a stock shock off pricepoint due to the proprietary thing that Spec. does with the rear shock. Any direction you can give me on this? I already talked to Push and they no longer support the machined back end of a Specialized rear shock, at least in the 2012 model. Bummer!