Well on my truck (has a 454) I have 50 series Flowmasters, I don't care for that sound, it's not a rumble type of sound that you are probably trying to describe, I know what you mean. Also some radical cams will help you with that rumble. But yeah I wan't to know what kind of exhaust system people are using to get that kind of sound as well. I though about the dynomax one's too but I don't know. Maybe just make your own with a cat and no muffle or neither.