That was one reason I chose the tti, they make headpipes specifically for the gear vendor clearance. The cam is just 246/254 so it is fairly mild but adding to the diameter is going to make the sound more aggressive and the engine will see more load with the tight converter which will add to the sound. I just hope that I won't get into the dreaded "drone". Being able to install myself without going to a muffler shop and the 13 positive responses about the tti system that I got here, sealed the deal.