The DFMU that comes with the kit is ok on stock boost if you have timing retard. But you would need some bigger injectors and a piggyback to tune them with when you increase the boost. Some people successfully ran 440cc injectors with SplitSecond piggyback, so you might want to see if any Vortech guys are selling there SS box. You might find one for cheap. As for the J&S, you can tune the timing retard with the piggyback (SS or Greddy) then use the J&S to retard timing when you have knock.