I used Flowmaster resonators (15150S) on my 2.5" TTI exhaust system that was very noisy and droned on my 6.1 Hemi. These are true "resonators" (ie have a tuned parallel tube but are straight through. Totally fixed my problem.
I see they also have 3" ones. https://www.flowmastermufflers.com/accessories-and-tips/?sub2=Resonator&realkeyword=resonator.
Jim