So I have a 06 with the 5.7. Ive been noticing that between like 2000-2300 rpm area there is a loud dronning sound. The speed doesnt matter, 5mph, 37mph, 78mph...etc... If its in the rpm range it makes the noise. From my understanding these hemi engines, while VERY great engines, early models did have a tendancy to break header bolts creating exhaust leaks. Im thinking that exhaust gasses and pressures are creating the harmonics that make this sound. But im not 100% certain. Anyone have any ideas what i could do to test if this is what is indeed happening or possible look at something else? Ive only owned this for about 2 weeks and to my knowledge its 100% stock.