Wow, kinda thin on the replies here!
Just assuming you haven't done any research, maybe you'd be willing to know what I've found out. Be warned, this is information I've learned mostly from this site and not from hands-on experience.
The Thunder Header is supposed to be your best bet in performance. Simply put, the 2 into 1 exhaust system should give you more "Grunt" at the lower RPMs due to an improved scavenging effect.
The True Duals have the benefit of just dripping with style! There is no scavenging effect since the two pipes are completely independent. You may get an improved high RPM benefit.
Both will offer increased exhaust flow and better sounding tones than factory pipes. Increased exhaust flow is not always best for performance.
Louder does not always mean faster.
My choice was simple... I wanted a little better tone,and a little more performance. I went with a pair of "Slip Ons".
Hope this helps!
Cheers!
