Building the correct tone for a classic car's exhaust is one of the last decisions in a restoration and one of the most impactful on the driving experience.

The factory exhaust on most muscle cars was quiet by the standards of modified cars — it had to be, for liability and noise regulation reasons. The factory exhaust on a Z/28 or Boss 302 was louder than an economy car but quieter than a racing engine.

For a street car that you'll drive regularly, the Flowmaster 40 series or the Magnaflow chambered muffler are the common choices. Both produce a tone that sounds period-correct without being oppressive on a long drive. The Flowmaster has more interior resonance at cruise; the Magnaflow is quieter on the highway.

For a show car or occasional driver, a louder note is more acceptable. For a daily or road trip car, err toward the factory-like tone.