I am glad the stock shackle seems to work for everyone. Looking at it though, you can see my where my concern is coming from, the shackle is a little bit thicker than sheetmetal.
My lift blocks introduce no vibrations in the driveline, at least mine don't seem to. I am glad that was brought up, although it seems like you have to pry this info out of people. Most people say "it works great" and never mention some of the other stuff. It sounds like if I don't want to mess with shims/blocks for the rearend, it's not going to work very well.
And I think we need to discuss more about the wheel centering in the wheel opening. Does everyone have this problem and ignore it or have another little trick to correct it? I really think if more parts are needed to make this work properly, Sky Manufacturing and others should include the necessary parts in their kits. Or have it in bold letters what else you need and where to get it.