Due to the popularity of the 188-220, we have decided to keep it at $599 as we are having it mass produced now. Another highlight is that we have changed the Lobe Separation Angle, or LSA. It is now on a 109.75 LSA with the intake just over 99 degrees, which will give more clearance for you 12v guys or people that hve had their block or head cut on the 24v's