They like to send garbage and Im sure they are over charging you some how on that kit. But Im not sure the price of 5 lug kits these days. Just saying beware of that company I had a run in with them years ago sent me junk parts. They may have changed their ways but unlikley.
you can source the same parts in any JY or off CL. LMRS sells a cheap 5 lug kit as well. There's a great site that has everything you need to know about brake upgrades. I'm sure someone will post it.
Their ads are misleading. They cherry pick the nicest looking kit, but if you read the fine print, it's not what they send you.
They claim the kit has everything you need, but at the end they want you to pay extra for the MC, booster and prop valve and another $200 for 94-95 spindles.
Just piece the kit yourself. For what you will spend with their GT kits, you could put yourself together a m2300k cobra kit.