You've known about (and heard!) Flowmaster's high-performance mufflers for a long time. Now, here's something for your '75-later car or truck: Flowmaster's Direct-Fit high-flow catalytic converters.
Flowmaster Direct-Fit high flow catalytic converters are 49-state legal and are exact replacements for your blown-out, worn-out or missing OE units. They're engineered for long life, and meet or exceed OEM and USEPA standards. (They're working on California CARB certification.)