RE: THE UNOFFICIAL SHOCKWAVE 36 THREAD
The stock tuned pipe is fine, Most the vids you see are engines with All the Shims still in and Novice tuning.
After the engine is broke in and Prop, Strut, and trim tabs Dialed in you can trim about 1\8" at a time off the header to get it in the higher RPM Range. Matching the Header inlet to the Exhaust Port on the engine will improve flow and performance also.
Motoman25 has posted a good vid a couple pages back and some of what he did to get er going good, Maybe he will chime back in and give you a little more insight.
This is HIS Vid
[youtube]http://www.youtube.com/watch?v=lcKI7pr3GVM[/youtube]