As an engineer, I disagree with the 'we've squeezed out all we can' statement...
We intentionally make everything capable of three times the power that the customer gets for a stock machine. That way, when they show up on a forum like this, we are the heroes for telling them how to turn up the power!!
On a Super M, there is a little screw on the left side. In for more power, out for less... You can put in a longer screw if you need.
Seriously, talk to your local machine shop. As with most powersports, power = $$$. You can do a lot with the right money and skills...Your engine is an air pump. Keep that in mind!
IowaAndy