I have an '04 Tahoe with K&N FIPK and a 40 Series Flowmaster. While I like the grunt of the FLowmaster, the resonance inside is killing me. It makes the thing almost unbearable to drive at interstate speeds. Add to this, we use to pull a trailer fairly often and with the resonance beingright at the "sweet spot" (2100 RPM) it bothers the crap outta me.

I wanted a 3 chamber, but the moron at the muffler shop put on a 40 series. It was loud.. but not too loud. As time has wore on, it has gotten louder, though. I had considered trying to insulate the exterior using some muffler packing for ATVs and MX bikes, and wrapping that with some header wrap.... any opinons on if that would actually help?

No tip(s). Just had the OEM muffler cut out and the Flowmaster welded in. OEM outlet. I'd post the link to the audio file I have of the exhaust... but my website is free and the bandwidth is limited. One download and my site goes down for an hour.

Any opinions on a quality muffler that has no interior resonance, but still packs a deep throaty growl like the Flowmaster?

Thanks!