I ran a Thunderheader on my Night Train which had the 95 c.i. Big Bore Kit, cams, 42 mm Mikuni, HC forged pistons, shaved heads, etectera. The pipe works but you have to get used to thesound compared to the ubiquitous drag pipes or Street Sweepers. My new Bob is getting a Thunderheader, SE A/C andPower Commander III a.s.a.p. - certainly before Bike Week!

 

Two into one systems typically provide more torque /HP than drag pipes, etc.. but I still like the looks and sound of two into two systems.