Description
Overview
The Flowmaster 40 Series Chambered Muffler is the muffler that built the legend. As the Original 40 Series, this flowmaster muffler delivers the deep, aggressive exterior and interior tone that made the Flowmaster company a household name among performance enthusiasts. If you’re chasing that unmistakable original Flowmaster sound, this is the exhaust muffler for you.
Built as a true chambered performance muffler, the 40 Series produces an aggressive sound level that announces your build the moment you fire it up. It’s engineered for drivers who want their car muffler to make a statement — bold, throaty, and instantly recognizable as genuine flowmaster exhaust.
Built to Last
Durability is at the core of this flowmaster 40 muffler. It’s constructed of 16 gauge aluminized steel and fully MIG welded for maximum strength, then finished in high-temperature paint to stand up to the demands of real-world driving. This is a muffler designed to keep sounding great mile after mile.
- Original 40 Series chambered design for that classic aggressive Flowmaster tone
- 16 gauge aluminized steel construction, fully MIG welded for maximum durability
- High-temperature paint finish
- 3.00″ inlet diameter with a 9.50″ body width
- Aggressive sound level, inside and out
- Universal fitment, ideal for street rod applications
Sound & Performance
Among performance mufflers, the flowmaster 40 series stands apart for its unapologetically loud, deep character. The chambered internals give you that raw, race-inspired growl that fans of flowmaster exhaust systems have loved for decades. Whether you’re finishing a street rod build or upgrading a daily driver that needs more attitude, this performance muffler brings the sound your project deserves.
Fitment & Configuration
This is a universal-fit exhaust muffler with a 3.00″ inlet diameter and a 9.50″ body width, making it a versatile choice for a wide range of custom flowmaster exhaust system layouts. It carries Emission Code 5 and is well suited to street rod vehicle types. Please note that new hangers are required and are not included, and exhaust tips are sold separately, so you can tailor the installation to your specific setup.
Backed by the reputation of the Flowmaster company, the 40 Series remains one of the most iconic mufflers ever offered. When you want authentic Flowmaster attitude and proven, MIG-welded aluminized steel construction, the Original 40 Series delivers the tone and toughness that made these performance mufflers famous.













