817663 Flowmaster's American Thunder cat-back exhaust system for the 1998-2003 Ford F-150 pickup truck is perfect for the person looking for an aggressive exterior sound level with all of the performance benefits that you would expect from Flowmaster. This system allows you the choice of either dual out the rear exit tailpipes, or dual out the sides behind the rear wheels, which is perfect for towing. The bolt-on 409S stainless steel system fits both the 4.6L and the 5.4L V8 engines and features a Super 40 Series performance muffler and dual 2.50-inch mandrel-bent tailpipes finished off with a pair of large 3.50-inch polished stainless steel tips. This system is designed to fit all 2/4 wheel drives, all wheelbases and is covered by our Lifetime Limited Warranty. Designed for an easy fit, this system includes all necessary parts and hardware for installation. Features: Large 3.50-inch Polished 304 Stainless Steel Tips Dual Outlet Super 40 Series Performance Muffler Mandrel-bent Stainless Steel Construction Aggressive Exterior Performance Tone Uses the Factory Hanger Locations Multiple Exit Styles Provided in Kit Clears the Factory Spare Tire Lifetime Limited Warranty Moderate Interior Tone Easy Installation About Flowmaster Flowmaster® is a household name, and for good reason. They've built legendary exhaust systems and mufflers for decades, and now offer performance air intakes, catalytic converters, and headers to give your hot rod performance to match the iconic Flowmaster sound. SPECS 2WD/4WD RWD/4WD Brand Flowmaster Emission Code 5 Exhaust Series American Thunder Exit Position Dual Out Rear / Dual Out Side Heat Shield No Inlet Diameter (in) 2.5 Material 409 Stainless Steel Muffler Part Number Kit Only Muffler Quantity 1 Muffler Series Super 40 Series Outlet Diameter (in) 2.5 Product Type Exhaust System Single Dual Dual Sound Level Aggressive System Type Cat-back Tip Diameter (in) 3.5 Tip Length (in) 13 Tip Quantity 2 Tubing Diameter (in) 2.5 UPC 700042029945 California Proposition 65 Chemical Name Chromium (hexavalent compounds) Nickel (Metallic) California Proposition 65 Required Yes Part Number 817663 Instructions for Part# 817663 Warranty for Part# 817663 Fits 1998-2003 Ford F-150 with 4.6L or 5.4L engine. Fits both 2/4-wheel drive models.