I seem to recall that the length of the intake manifolds is the prime reason why the SS drops off so dramatically above around 7000 rpm. If you fit individual FCRs with shorter Malossi intakes I'm sure the power continues past it's current peak. There's a page here that goes into it a bit
http://www.visi.com/~moperfserv/carbs.htm What do the SSie's rev to?
One thing that strikes me about Chi's bike isn't so much the 18 % gain but more the lousy performance before the work. From 4000 rpm onwards it's all over the place. My K&N'd but otherwise standard SL made 73hp last time it went on a dyno. It's difficult to compare bikes power outputs from different dynos but were we to equate Chi's first run with my standard bike then his second run would be in the mid 90s..... Does that make sense?