Summit showed valve stem seals for the Trick Flow 190’s as being out of stock with no other info. Instead of talking to some girl working at home sitting in bed with her laptop and asking her what’s up with the seals, I called Trick Flow and talked to some dude who knew what a valve stem seal was, he said go ahead and order it, it’ll ship, they had them. As for the heads or anything else I’d call Trick Flow for usable info and then you will know what the real deal is