I have basically a MBRP type muffler, spiraled louvers straight thru. Too loud so I turned it around-louvers forward-helped, quieter but still good tone, but noticed a little less flow performance wise. Thinking about turning muffler back around and adding a resonator. Want to confirm adding a resonator will not inhibit the flow? Wondering if anybody has experience with the resonator on the duramax? Good sound but quieter? No drone?

Do a search on Resonator. By far the best money I spent on sound comfort. Craig sells a good one and it'll get rid of the drone.

I now have the aero-turbine 4040L resonated muffler and it is extremely quiet, just like stock or better. Flow is great. 4" in and out. www.aero-turbine.com is where I purchased.

put a MBRP resonator on my 03 extended cab 4x4 , i had a bad drone and it took care of it, however I had to do some modifications to the down pipe due to room constraints cut 7.5" off of down pipe in front of flange to move flange foreward and rewelded it on worked just fine, if you have a crew cab i would think you have plenty of room for the resonator, it measures 18" overall length, I left it and the muffler backwards because i want quiet, but it still sounds real good. had them both ways couldnt really see any EGT temp difference.

Thanks. Was there any or much difference in sound with louvers forward vs backward? And I do have a crew so should have plenty of room. This thing is basically a real small muffler, correct?

I also added the MBRP resonator to my exhaust system. I didn't notice any change in tone with the louvers forward or back. It did a decent job to quiet down the 1800-2000 rpm "noise", but still not gone. Very quiet at all the other rpms though. I installed the resonator in a new front pipe I also bought from Mark Craig. Here is a pic of how I installed it in the front pipe.
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