I don't remember what the stock exhaust sounded like (I did own a '73 in '82!), but on a 2.5" exhaust, I just put a "Meineke" 24 inch resonator (4024005S, $60) just aft of the headers, and a Flowmaster (12514310) DBX Muffler in and it sounds absolutely awesome. Not very loud at idle or when not pushing it, but gives that wonderful sound under load. I highly recommend this combination! The resonator has a spiral of curved scoops inside, and we installed it with the scoops grabbing into the flow. They said that gives a little more dampening, and that is what I wanted... btw, Meineke did an excellent job of bending pipe and welding - all for $180. I supplied the Flowmaster from Amazon ($150). Stephen