exhaust drone/harmonic resonance

Here is what I have. Stock exhaust manifolds (70 340) TTI down pipes, TTI X pipe, Had dynomax super turbos took them off and tried spintech sportman 3000. TTI over the axle tail pipes and TTI tips. The car sounds great from the outside. But inside it hurts your ears annoying resonating just want to jump out kind of noise. I talked to Ron at spintech and he suggested trying resonators in the tail pipe area. There doesn't seem to be enough room. Has anybody had any luck with this? I have way too much money invested in this to give up on it, any ideas would be appreciated.

Thanks for posting this....I have 67 barracuda coupe, mostly stock 360 w/340 manifolds. Here in the next week or so I am getting ready to order that exact same kit and have been wondering what those dynomax mufflers sounded like inside the car. Having been inside other cars with magnaflow muffers and felt like there was little to no drone I think I am going to give them a try.

Did you install the kit yourself...if so what did you think? Do the pipes need to be cut to fit or do they line up? Might be a good reason to buy a chop saw.


Having read this thread, I saw some of you layed sound deadener inside the car. Has anybody done a before and after test?? or even with a decible meter? I guess I am asking is it worth the effort and cost??

Thanks Jim