Quote from round2KAfter reviewing the various drawings it is clear that the system on the Mustangs and Fairlanes was named the Arvinode...the first image is typical of the system found on Fairlanes with a quarter wave tube in the resonator.
That's exactly right. I remember seeing the "quarter wave tube" inside the resonators on my '64 HiPo Fairlane. It was just visible at the outlet, and it looked like there was a rod or tube stuck inside the resonator body. I always thought that it was one of the more unique physical parts of the system.