Product Description
MBRP M1004A is a universal, quiet-tone diesel muffler built from aluminized steel with a 4" inlet/4" outlet, a 24" body, ~6" case diameter, and 30" overall length. It tames drone while keeping flow for tuned diesel trucks and 4" systems.
Key Specs
- Material: Aluminized steel
- Inlet/Outlet: 4" ID / 4" ID (single in / single out)
- Body Length: 24" | Overall Length: 30"
- Case Diameter: ~6"
- Configuration: Straight-through, quiet-tone
Fitment
Universal fit for 4-inch exhaust systems. Common on diesel trucks such as Ram Cummins, Ford Power Stroke, and GM Duramax using 4" piping. Verify space for a 30" overall muffler and 6" case before ordering. Orientation can be installed either direction unless otherwise specified.
Cross-Reference / Alternatives (MBRP Only)
- Stainless equivalent: MBRP M1004S (T409 Stainless)
- Premium stainless replacement (30" overall): MBRP M1031 (T304)
- Budget high-flow 30" muffler: MBRP GP015
- Tone finisher / drone control: MBRP R1009 Resonator
- Bypass (no muffler) stainless: MBRP MDS30
- Stainless 30" universal replacement: MBRP M91031 (T409)
Install Notes
Universal component—cut/fit/weld (or clamp) into any 4" section. Check local sound and emissions regulations before modifying exhaust.
FAQ
Will M1004A fit my truck?
Yes, if your system uses 4" tubing and you have ~30" of straight length available. Measure before purchase.
How quiet is the “Quiet Tone” compared to straight pipe?
Noticeably quieter with reduced drone while keeping strong flow—ideal for tow rigs and daily drivers.
Do I need to weld it?
Welding is recommended for durability, though quality 4" band clamps can work if the mating pipes are clean and properly overlapped.
What’s the difference between M1004A and M1004S?
M1004A is aluminized steel (budget-friendly). M1004S is T409 stainless (better corrosion resistance).