aFe Large Bore-HD Cat-Back Exhaust

2004–2007 Dodge Ram 2500 / 3500 5.9L / 5.9L Cummins

Part #: 49-42002

Overview

The aFe Large Bore-HD Cat-Back Exhaust System is a precision-engineered upgrade designed specifically for 2004 to 2007 Dodge Ram 2500 and Ram 3500 trucks equipped with the 5.9L and 5.9L Cummins engines. This cat-back system replaces the factory exhaust with high-quality mandrel-bent 409 stainless steel tubing, delivering improved exhaust flow and enhanced engine performance. Ideal for truck enthusiasts and heavy-duty users, it offers a robust solution to increase horsepower, torque, and reduce exhaust gas temperatures while providing a bold, aggressive exhaust tone.

Built to withstand demanding conditions, the Large Bore-HD system is perfect for towing, hauling, and off-road applications where durability and performance are critical. Its polished stainless steel tip adds a sleek, professional finish to your truck’s rear appearance.

Key Features

Combining advanced engineering with premium materials, the aFe Large Bore-HD Cat-Back Exhaust System offers significant performance and sound improvements. Key features include:

• 4-inch mandrel-bent 409 stainless steel tubing for maximum exhaust flow and corrosion resistance
• High-flow, straight-through perforated muffler measuring 8" diameter by 30" length for aggressive sound and minimal restriction
• Muffler delete pipe option included for a louder, more aggressive exhaust tone and increased flow
• Polished stainless steel exhaust tip for a clean, finished look
• Bayonet-style hangers with swaged ends for secure, rattle-free installation
• Slotted and swedged pipe ends paired with premium band clamps to ensure a tight, leak-free seal
• Engineered and tested on flow benches and dynamometers to optimize pipe diameter and muffler design
• Improves exhaust flow by up to 29%, reducing exhaust gas temperatures by up to 100°F
• Constructed in the USA with a 2-year limited warranty

Construction & Design

The Large Bore-HD Cat-Back Exhaust System is constructed from durable 409 stainless steel, chosen for its excellent resistance to corrosion and ability to withstand high temperatures common in heavy-duty diesel applications. All tubing is mandrel bent to maintain a consistent diameter through bends, preventing flow restrictions that can occur with traditional crush bends. This design ensures smooth, unrestricted exhaust flow, maximizing performance gains.

Each hanger is fully welded on both sides and features swaged bayonet ends that lock securely into the factory mounting points, providing a stable and vibration-free fit. The system’s slotted and swedged pipe ends, combined with premium band clamps, create a tight seal that resists leaks over time. The two-piece tailpipe design allows for precise adjustment during installation to ensure perfect alignment and clearance.

Performance & Sound

Engineered to enhance both power and sound, this cat-back exhaust system increases exhaust flow by up to 29%, contributing to improved horsepower and torque output. It also lowers exhaust gas temperatures by as much as 100°F, helping maintain engine efficiency and longevity under heavy loads. The included straight-through perforated muffler delivers an aggressive and loud exhaust note that complements the truck’s heavy-duty character. For those seeking an even more pronounced sound and maximum flow, the muffler delete pipe option allows customization of the exhaust tone to suit personal preference.

Installation & Fitment

The aFe Large Bore-HD Cat-Back Exhaust System is designed as a direct bolt-on replacement for the factory exhaust on 2004–2007 Dodge Ram 2500 and 3500 trucks with 5.9L or 5.9L Cummins engines. Installation uses existing factory mounting points with no modifications required, making the upgrade straightforward. The system includes all necessary clamps, hangers, and detailed instructions to facilitate a smooth installation process. The two-piece tailpipe design allows for easy adjustment to achieve perfect alignment and clearance.

What's Included

• 4-inch mandrel-bent 409 stainless steel tubing
• 8" diameter by 30" length straight-through perforated muffler
• Muffler delete pipe for aggressive sound option
• Polished stainless steel exhaust tip
• Premium band clamps
• Bayonet-style hangers with swaged ends
• Detailed installation instructions

Ideal For

This exhaust system is perfect for Dodge Ram 2500 and 3500 owners from model years 2004 to 2007 who want to enhance their truck’s performance, sound, and durability. It is especially suited for heavy-duty users who demand improved horsepower and torque for towing, hauling, or off-road applications, while also appreciating a bold, aggressive exhaust tone that matches the rugged character of their truck.

aFe POWER (Advanced FLOW Engineering) offers dyno-proven intake, filtration, and exhaust upgrades aimed at measurable performance gains. The brand’s lineup is geared toward enthusiasts looking for better airflow, improved sound, and durable materials—from cold air intakes to stainless exhaust systems for street and track applications.