Well I completed my muffler modification and installed my Areo 4040 resonator. I haven't been able to get her out on the road yet but at idle I can not tell a sound differnce. It was a pretty straight forward easy job. I do have a suggestion for anyone planing this type of work....go speak to your local school bus garage. They may have muffler sections and/or parts that are obsolete for their fleet. I obtained a scrap (brand new) complete "4 muffler pipe section to use. It was from a Blue Bird bus that the school no longer had and was taking up space in their storage.
With that pipe I was able to measure and cut sections off to match up for my placement of the Areo. The old muffler (heavy as hell so have some one there to help) took up a lot of room so the Areo is in the same spot using the same U mounts that are welded to the frame.
We head to FL on February so I'll report back on the sound level after the trip. I'll apologize ahead of time for the photo quality in the posted pics.
you will love the change. Your muffler is small compared to the one that came out of my U-320...
Just a thought about resonators and noise.
Hearing any difference could be difficult as we all have different perceptions of what is noise and our hearing deteriorates with age ( don't tell the DW that mine does ).
There is an app ( at least one ) for your smart phone that will measure the decibel level accurately so to determine the reduction in noise level or increase simply use that.
The one I use is called simply " Sound Level ", there are probably others, this one was free at the Apple App store.
Gary B