As others have stated TFI makes the most sense, it can be done right now, after the $200 investment...you are set, with whatever mods you add in the under 5,000 RPM range we all for the most part live..."--in the real world." Atmospheric gains beyond 5,000 RPM really have no place in Stage I...only if you start messing with cams and internals will you even "begin" to extract any decent power in that RPM band, but for what purpose?...certainly not on street riding...why pound your wallet into the dirt to go that route? JMHO