So got the elevate kit on my 19. Have to say they have great instructions for the spindles, which I would never need. And no real instructions for the rear other than bolt hole placement. Couple things I don't understand is the front arm mount has way too big of a hole for the stock bolt. Luckily I had some random spacers sitting around that were a perfect fit to fill the void and bolt. Next is the caps for the rails. I ground them down to fit flush to the hifax and get the bolt hole lined up. If you just cut back the hifax and mount the cap like stock there is too much of a step between the two. Instructions just say to cut the back of the hifax and don't say to cut the front. One of my rails didn't have the hifax hole for the bolt drilled out, so had to do that so the bolt would self tap in.
The only thing I see different about the rear from stock is the ice age rails tip up futher in the front and are a bit longer. As far as mounting, you drill out the lower hole in the inner tunnel plate for the front arm mount, and use the lower hole for the rear arm mount. I can see why guys are just mounting the spindles up to the alpha and just using these same holes in the skid for the arms.