"Made from T-304 stainless steel, Mandrel bent tubing, CNC Machined Flanges. Each set is tested and dyno'd for maximum performance."
I guess not then ,but certainly a good price.(I still think 4-2-1 is way to go)
the resonance you are getting will require a front chamber to the exhaust ,I doubt altering the rear box will help very much,give me a call ,as I have some front pipes here.The filter kit may produce better results with a pulley fitted,as the charger demands more air,how the manifold flows with the pulley is a bit of pot luck,may work better or worse ,I suspect better though.nice to see actuals rather than claims!!