Flowmaster Flow FX Cat-Back Exhaust For 1999-2007 GMC/Chevy 1500 4.3L/4.8L/5.3L 2003-2004 5.9l 24v cummins spring loaded cylinder and pressure

spring loaded cylinder and pressure regulation provides up to 150 retarding horsepower throughout the engine's RPM range - not just at high rpm like some designs that use holes or additional parts and claim it as a better idea

and application-specific valving for smooth control on and off the road

These units featured on demand lockup and the rigidity of a billet channel casting

Iridium Blue Medium color visor

The EGT probe can easily be installed in the exhaust manifold for the most accurate cylinder temps

Flowmaster Flow FX Cat-Back Exhaust For 1999-2007 GMC/Chevy 1500 4.3L/4.8L/5.3L 2003-2004 5.9l 24v cummins spring loaded cylinder and pressureThis Flowmaster Flow FX cat back exhaust system for the 1999 2006 GM 1500 trucks (2007 1500 Classic) with the 4. 3, 4. 8, or 5. 3 liter engine (Crew Cab 5. 5' bed, Extra Cab 6. 5' bed only) is manufactured using durable 409 stainless steel throughout and features 3. 00 to dual 2. 50 inch mandrel bent pipes for better exhaust gas flow. A Flow FX "straight through" muffler is used for a moderate to mild sound level and maximum performance. Maximum