Product Specifications
KA24E Headers for 1990–1995 Nissan Hardbody D21 4WD
Replace an aging cast exhaust manifold with a stainless steel header designed to give the exhaust path a smoother transition from the cylinder head. This Flashark header is listed for 1990–1995 Nissan Hardbody D21 pickups equipped with the 2.4L KA24E inline-four engine and 4WD drivetrain.
The 1.50-inch primary tubes lead into a 2.50-inch outlet, while the thick head and outlet flanges provide solid mounting surfaces. Silver and black finishes are available under separate SKUs.
Nissan Hardbody D21 Fitment
| Make | Model | Years | Engine | Drivetrain |
|---|---|---|---|---|
| Nissan | Hardbody D21 Pickup | 1990–1995 | 2.4L KA24E inline-four | 4WD / 4x4 only |
- Not intended for 2WD Nissan Hardbody models.
- Do not use this fitment for a KA24DE engine or a different Nissan platform.
- Existing exhaust modifications can change flange alignment and available clearance.
- Inspect the front driveshaft, steering components and surrounding underbody clearance before final tightening.
Technician’s note: Underbody clearance can vary with engine-mount condition, suspension height, previous repairs and the downstream exhaust position. Complete a full clearance check with the truck safely supported before operating the 4WD system.
Specifications
| Brand | FLASHARK |
|---|---|
| Part type | Exhaust header |
| Material | Stainless steel |
| Available finishes | Silver or black |
| Primary tube diameter | 1.50 inches |
| Outlet diameter | 2.50 inches |
| Cylinder-head flange thickness | 7/16 inch |
| Outlet flange thickness | 3/8 inch |
| Silver SKU | FLES08217 |
| Black SKU | FLES08358 |
| Product model references | EH28949X / ES08217 and EH28950X / ES08358 |
Key Features
- Designed around the 2.4L KA24E exhaust-port layout used in the listed Nissan Hardbody D21 4WD applications.
- Individual 1.50-inch primary tubes provide a smoother exhaust path than the compact cast-manifold layout.
- 2.50-inch collector outlet for connection to the remaining exhaust system.
- Stainless steel construction with silver and black finish options.
- 7/16-inch head flange and 3/8-inch outlet flange provide substantial mounting surfaces.
- Useful as a replacement or upgrade when the original cast manifold is cracked, leaking or heavily corroded.
Built for Better Exhaust Flow and a More Defined Tone
A tubular header gives each cylinder a more direct path into the collector. On a naturally aspirated KA24E, that layout can reduce restriction and support sharper throttle response and smoother exhaust movement, especially when the remaining exhaust system is in good condition.
The final sound depends on the catalytic converter, pipe diameter, resonator, muffler and exhaust-leak condition. A header can make the engine sound deeper and more mechanical, but it does not determine the complete exhaust tone by itself.
Stock Manifold vs. Tubular Header
| Area | Factory-Style Cast Manifold | Flashark Tubular Header |
|---|---|---|
| Construction | Compact cast design | Stainless steel primary tubes |
| Exhaust path | Short shared passages | Individual tubes merging at the collector |
| Outlet | Vehicle-specific factory connection | 2.50-inch outlet |
| Sound | Factory exhaust character | Can add a deeper, more defined mechanical tone |
| Installation check | Original equipment layout | Requires flange, sensor, steering and front-driveshaft clearance checks |
Header vs. Complete Nissan Hardbody Exhaust System
This product is an exhaust header, not a complete Nissan Hardbody exhaust system. It replaces the engine-side manifold section and connects the cylinder head to the downstream exhaust path.
A complete Nissan D21 exhaust can also include connecting pipes, a catalytic converter, resonator, muffler and tailpipe. The condition and design of those parts will affect sound, exhaust flow, installation and emissions performance.
For other exhaust components, visit the Flashark Exhaust Header collection.
Package and Installation Planning
Package contents vary by selected SKU. Select the required finish and SKU before ordering, and contact customer support if you need help identifying the correct configuration.
- Allow the engine and exhaust system to cool completely before removal.
- Inspect the cylinder-head sealing surface and downstream flange before installing the header.
- Replace damaged sealing components rather than reusing parts with visible crushing, cracking or heat damage.
- Start all fasteners before final tightening so the header and downstream exhaust can settle into alignment.
- Check the O2 sensor wiring path and keep the harness away from hot tubes and moving parts.
- Inspect clearance around the front driveshaft, steering system, transmission and underbody before starting the engine.
- Recheck fasteners and inspect for exhaust leaks after the first complete heat cycle.
Who This Header Is Best For
- Owners of a listed 1990–1995 Nissan Hardbody D21 4WD with a 2.4L KA24E engine.
- Trucks with a cracked, leaking or heavily corroded factory exhaust manifold.
- Owners looking for a stainless tubular header and a more defined exhaust tone.
- Buyers prepared to inspect drivetrain and exhaust clearance during installation.
- Vehicles whose downstream exhaust components are in serviceable condition or are being upgraded as part of the same project.
Who Should Choose a Different Part
- Owners of a 2WD Nissan Hardbody.
- Vehicles equipped with a KA24DE, Z24, V6 or another engine not listed in the fitment table.
- Buyers looking for a complete cat-back exhaust, muffler or full Nissan D21 exhaust system.
- Owners who cannot inspect front-driveshaft and steering clearance during installation.
- Vehicles that require a certified emissions replacement without supporting product-specific approval.
- Drivers who want to retain completely stock exhaust sound and construction.
Emissions and Street-Use Notice
Do not remove, bypass or disable the catalytic converter, O2 sensor or other emissions equipment when installing this header. Exhaust and emissions requirements vary by location. Check the rules that apply to your vehicle before installation or road use.
Shipping & Returns
Free U.S. Shipping: Orders are typically processed within 1–2 business days and delivered within 7–9 business days. Additional charges may apply to remote areas.
30-Day Returns: Unopened and unused items in their original packaging may be returned within 30 days of receipt. Return shipping is covered for verified quality issues.
Worry-Free Delivery: Optional protection against eligible loss, theft, delay, or transit damage is available at checkout.
