That is a nice looking graph.
The only thing I noticed is the torque drops off rather fast. (i.e. faster then it should above 6k IMO)
Your exhaust is likely not very free flowing??? (i.e stock mufflers!)
Also 12-12.5 to is VERY rich for NA. Try around 12.8 to 13 This could also help out the power above 6k.
I probably wouldn't push it over 13 to 1 on the reformulated liberal piss they make you suffer through in CA.

Plus the spike above 180 at the end doesn't count.

Just out of curiousity. Return or returnless???