Lesson learned: Measuring interior noise on a vehicle has a lot of variables. Bumps, wind hitting the truck, and other traffic really mess with having a standardized process.
This was done on the same length of road, with other vehicles at least 50 feet away. The readings are the lowest recorded, hoping that it represents the vehicle and not the external elements acting on the sound(see above).
Stock Connis, 10% Tread
40 MPH 59db
50 MPH 65db
60 MPH 66db
70 MPH 68db
Duratrac, New
40 MPH 61db
50 MPH 65db
60 MPH 65db
70 MPH 69db
Not much to see.. I think that what is happening is that there is a new tone being introduced with the Duratracs (the slight hum on the highway), but it is not at a db level that affects the overall interior noise that much. The wife, son, and I think that the largest contributor to noise is simply the wind hitting the windshield. I guess the Cooper Zeons would be comparable in noise, as the tread isn't incredibly different.. All in all, I am 100% glad I did it.. The hum is -barely- noticeable, it looks great, and I haul Cub Scouts all over God's creation too much to risk the Connis getting me stuck.
Glamour shots, before and after: