Heavy‑Duty Intake Manifold Kit for Jeep YJ 4.0L

Product Introduction

This stainless steel intake manifold kit is designed specifically for the 4.0 L inline-six Jeep Wrangler YJ (1991–1995). Manufactured with precision CNC machining and TIG welding, the assembly delivers tight tolerance, corrosion resistance, and improved airflow over stock manifolds. 

As an industrial solution for performance shops or aftermarket distributors, this kit supports OEM-level performance with the added robustness needed for high-demand environments. Thinking beyond the Jeep YJ enthusiast market, manufacturing partners can integrate this manifold into rebuild kits or performance lineups.

Features & Benefits

The manifold' precision-crafted ports improve airflow efficiency, reducing turbulence and enhancing throttle response. The stainless steel construction withstands high heat cycles and resists corrosion, ensuring longevity — qualities essential for performance applications, fleet service vehicles, or custom Jeep builds. 

Flanges are thickened and fully machined for proper sealing. This manifold is suitable for integration with related parts like throttle bodies or intake plenum systems commonly supplied in industrial kits.

In addition to the stainless steel exhaust manifold itself, this kit includes all necessary mounting and sealing accessories to streamline installation and ensure proper long-term performance. Each component is carefully selected or custom-manufactured to meet the same durability and dimensional accuracy standards as the manifold.

The multi-layer metal (MLS) exhaust gaskets are designed to maintain a reliable seal under thermal expansion and vibration, reducing the risk of exhaust leaks and noise. These gaskets match OEM port geometry and are compatible with both stock and aftermarket cylinder heads.

The spring-loaded bolts and studs allow for controlled expansion and contraction of the exhaust assembly, minimizing stress on the manifold flange and ensuring consistent pressure on the sealing surfaces. These hardware components are made from heat-treated steel with corrosion-resistant coating for extended durability in high-heat environments.

The U-shaped exhaust support bracket adds mechanical stability to the lower exhaust connection, helping prevent fatigue or cracking at connection points. This bracket is pre-bent and sized for the Jeep YJ platform, making it a drop-in solution during installation.

Together, these components provide a complete bolt-on system for 1991–1995 Jeep Wrangler YJ exhaust manifold upgrades, making the product suitable not just for retail replacements, but also for B2B bulk integration into engine rebuild kits, performance upgrade packages, or fleet repair operations.

Technical Specs Table

FAQs

Q: Is this intake manifold compatible with EFI systems?
Yes, it retains the stock throttle-body interface and vacuum ports, making it EFI-compatible without modification.

Q: Can you supply custom port sizes?
Yes. We offer CNC porting services per customer specs, ideal for high-flow tuning applications.

Q: Are custom finishes available?
Yes. You can choose polished, brushed, or bead-blasted finishes depending on your project requirements.

Q: Do you offer related components like throttle bodies or gaskets?
Yes, we can bundle with throttle-body adapters, gasket kits, or intake plenum components for complete assembly packages.