I just purchased a catback Flowmaster Super 40 muffler with dual exhaust single in dual out. Does anyone anyone on here have this setup. If so does it have really bad interior resonance (sp?) I have not installed it but was just checking on the thoughts of others with this setup. Also does anyone have intake suggestions and does this exhaust have noticable HP gains?

 

I bought the 1-in-2-out FLOWMASTER and built the system in front and duals in the back. Major resonance in the cab. I welded in an 18-inch resonator in front of the muffler. It not only reduced the resonance to a acceptable level but I thinnk the resonator actually improved the power. This is my third Dak and 4th Dodge with FLOWMASTERs and I still swear by them.
Also have Airraid CAI. (4.7 2wd quad, automatic.)