Motorcycle Repair: exhaust, samson exhaust, thunderheader

Question
I have a 97 king with head work, aftermarket cam and ign and samson slip-ons it makes 80hp and94 ft lbs on the dyno, would putting a thunderheader on give a noticeable difference or should I leave it alone?

Answer
A thunderheader will not help. I would if I were U to get rid of the exhaust system you have as the Samson exhaust system are the worst I have ever tested on Harleys. You should Install a set of Cheap!!! and  nice looking and great sounding best performance exhaust on the market today anywhere in the country. CYCLE SHACK PHD 2" stepped duels. Expect to make about 10 to twelve horse power more and more usable torque accross the entire power band. Johnny