To my understanding it should help out significantly. There is the factor however of the exhaust timing no longer being correct, requiring some cam modification/replacement. Some one with more experience working on motors will have to speak up here.

 

it shouldnt damage the valves anyhow. The headers are long enough to prevent that. A rejet will be required tho and the ignition issue, if any, can be dealt with with a ignition advancer. BUT it will kill your bottom end, ie what lil bottom end torque it has now will poof, any performance gains will be on the top end and only with correct tuning. It will sound like shyt, you nieghbors will hate you, the LEO will LOVE YOU. Good luck, I would get a nice can for it myself