SLP Loudmouth II Exhaust, Loud Mouth II 99-04 Mustang GT/MACH 1 V8.
SLP’s Mustang cat-backs from LMPERFORMANCE have always been the best-performing exhaust systems in the business. Now they’re the most versatile, too! Using groundbreaking modular technology first seen on our Mustang X-pipes, we’ve developed a line of systems that can be quickly reconfigured to fit changing performance, noise-level, and sound-quality requirements. Simply loosen a few band clamps, swap muffler types, retighten, and you’re done. No other exhaust offers this level of performance and adaptability!
Along with the included race mufflers, the Loud Mouth II system is compatible with our original Loud Mouth™ resonators (#31062) and our all-new, straight-through-type Power-Flo™ traditional mufflers (#31065). Buy all three for complete control over your Mustang’s sound and performance characteristics.
NOTES: Includes Loud Mouth II race mufflers. Loud Mouth resonators and Power-Flo traditional mufflers sold separately.
FEATURES:
Includes Loud Mouth II bullet-type race mufflers for minimal restriction, reduced resonance, and an aggressive tone
Employs SLP’s exclusive modular technology, making it possible to switch between muffler and resonator types in a matter of minutes
Engineered and built to OEM standards to ensure proper fit
Constructed entirely from mandrel-bent stainless steel
Features show-quality polished mufflers and 3.5 double-wall tips with electromarked SLP logo
For 1999-2004 GT and Mach I models
Applications:
1999 - 2004 Ford Mustang
SLP Exhaust Type Descriptions/Definitions/Details: (use as a guide to the exhaust system on this page for details about the muffler type.)
Model
Type
Sound Characteristics*
Noise Level*
Bullet-Type Open Resonator (or muffler delete)
Extremely aggressive; powerful high- and mid-range tones with
moderate resonance
Muffling, Bullet- Type Resonator
Similar to original Loud Mouth, but with a throatier tone and reduced
resonance
Straight-Through "Traditional" Muffler
Deep, rich, and mellow; minimal resonance
*
Volume and sound quality will vary based on engine and exhaust-system
specifications. Loudmouth also refers to some systems without any resonators such as the 2010 Camaro Loud Mouth and the 2005 Mustang Loud Mouth Axle backs where the mufflers are removed altogether. Images below are representations in order to better understand the differences.
\ 
