New Ford 7.3l Godzilla V8

There are a number of different tunes out for it. The Premium Tune for motorhomes looks to be the default on E450s. When you hear it idle, it sounds like a muffled big block :)

https://fordauthority.com/2020/05/why-7-3l-ford-godzilla-v8-engine-offers-two-tunes-in-2021-e-series-exclusive/