All that is in there kit is a helix the bearing and some 66g belly busters. They have you use the stock springs. It is nothing special at all. If you have a stock sled in my opinion the 66g weighs are a little heavy at Alt. 8000+. I have there helix which is just a Venom helix that any one can order. I was already runner the 66g weights. I have the SLP pipe and run some different springs and some other adjustments and pull good R's notice no heat and it runs the same all day. I have worked on it the last two winters to get what I wanted but it works. I have an Assault with the chain case also.