Just a quick sample of some footage that I recently found I still had on tape of my old '87 Pontiac Formula Firebird with a stock 4-barrel 305. Exhaust was stock all the way back to the Moroso Spiral Flow muffler and single 3" outlet. Should've put the camera behind the car to get better sound, but it really didn't sound much different than what you hear in this video - had a nice growl at WOT, but it didn't drone at all and was pretty civil. Pretty good compact-sized muffler, really.
moroso, spiral flow, muffler, exhaust, 305, chevy, pontiac, firebird, formula, 4bbl