timing

better snap from low-midrange ...around 2 more pounds of torque
rejettting comes into play concerning ignition timing advances ..but going +4 shouldnt effect it enough to warrant a main jet change in most cases
 
well any time your making more power than stock your puttin more stress on the motor than you did when it was stock, but the bottom end and tranny on the blaster are pretty beefy, it'll handle about anything you throw at it.