I think I read on SPEEDTALK that flowmasters were not a very good muffler. NOT VENDOR BASHING just mentioning what I read...It seems that an engine builder on there had dyno data to back that up, but I can't say for sure they are not good mufflers..but if you aren't racing it doesn't mater I guess. I always liked the sound of plain jane turbo mufflers with a crossover pipe turned down no tail pipes. Nice and quiet(sorta) with a nice sound. I would never run dual exhaust without a crossover pipe..I HATE that cackling sound you get without it, if that makes sense.Almost like those hideous glass packs.