Exhaust Kit for Ford F-150 (1987-1996) 4.9L

Mandrel-Bent Dual Muffler-Back Exhaust Kit for 1987-1996 Ford F-150 (OBS)

What it Does: The dual muffler-back exhaust kit replaces the restrictive stock single tailpipe and baffled silencer on the 1987-1996 Ford F-150 to reduce exhaust backpressure and optimize scavenging on the inline-six engine.

The Stock Ford F-150 Exhaust Restriction

Factory exhaust configurations on the OBS F-150 rely on narrow-diameter, crush-bent tubing and heavily baffled OEM mufflers. Behind the catalytic converter, these restrictive press-bends create turbulent exhaust flow, choke low-RPM torque output on the Ford 300 Inline-6, and trap thermal energy under the bed. Decades of heat cycling also leave stock mild-steel joints and hangers severely corroded.

The Engineering Solution

This kit upgrades the rear section with a high-flow Flowsound two-chamber muffler engineered with a single 3-inch inlet and split dual 2.5-inch outlets. The tailpipes are mandrel-bent from 2.5-inch aluminized steel to preserve uniform internal diameter and eliminate restrictive pinch points. Designed to exit parallel to the frame rails, the geometry maintains clearance for the factory receiver hitch and OEM-diameter spare tire across all wheelbase configurations.

What's Included

• 1 Flowsound 2-chamber muffler (single 3" inlet, dual 2.5" outlets)
• 2 Aluminized mandrel-bent two-piece 2.5" tail pipes (slip-together)
• 8 Muffler clamps
• 1 Larger exhaust clamp
• 4 Rubber-insulated hangers

Technical Specifications

Compatibility

• 1987-1996 Ford F-150 4.9L Gasoline (Factory Single-Inlet Muffler Models Only)
• 1987-1996 Ford F-150 4.9L Flex-Fuel (Factory Single-Inlet Muffler Models Only)
• Fits all factory wheelbase lengths (Standard Cab, SuperCab, Short/Long Bed)

Frequently Asked Questions & Fitment Warnings

Does this fit the OBS F-150?

Yes, this is designed for the 1987-1996 Ford F-150 equipped with the Ford 300 Inline-6 engine. Excludes V8 models, configurations with dual-inlet factory mufflers, and any system modified ahead of the muffler inlet.

Is this exhaust kit a direct bolt-on installation?

No, this is not a direct bolt-on system; professional installation is recommended as pipe fabrication or trimming may be required, and non-stock suspension or tire setups will alter clearance.

The Ford Truck Durability Standard

Engineered for working trucks, this aluminized steel dual system delivers the corrosion resistance, thermal capacity, and low-RPM exhaust velocity required for heavy hauling and sustained towing.