My 66 Star Chief, with 389 2bbl. Stock headers and exhaust...but I cut everything off at the back of the rear doors, no mufflers at all. Havent driven it like this yet, but I like the way it sounds. Cheap and gives me the growl I want. Im sure it drones, but its a weekend cruiser, not a daily driver, so its all good.
Also, excuse the poor audio & video quality, it was taken on my cell phone. I will take a better video soon.
http://www.youtube.com/watch?v=zPzGlrBsOnI&feature=plcp