SEMA 2025: Holley Offers A Complete Fox Mustang Fuel System Upgrade

Holley’s new Fox Fuel System Kits take the guesswork out of upgrading the fuel system in your fuel-injected 5.0-liter 1986-1993 Mustang. Designed as direct replacements for the factory setup, these kits include everything you need, including the fuel pump module, filters, braided fuel lines, fittings, clamps, hardware, and an electric pump wiring harness. The result is a clean, OEM-style installation that doesn’t require major modifications or custom fabrication.

Whether you’re running a stock engine or a high-output EFI build, Holley’s kit (P/N 526-25) is engineered to handle it. Pump gas and E85 compatible, it comes with either a 340- or 525-liter-per-hour fuel pump module, a billet filter, and a fuel pressure regulator with gauge. Forty feet of -6AN or -8AN braided hose is included, enough to run feed and return lines from tank to engine, along with all the AN fittings and EFI-rated clamps needed for a polished, reliable system.

Holley designed the kits to use as much of the original chassis and sheet metal routing as possible, keeping installation straightforward and clean. Minimal to no drilling is required, so the system integrates neatly with your Mustang’s factory layout. 

A new electric fuel pump harness and relay wiring kit ensures the pump receives proper amperage, improving reliability and keeping fuel pressure steady under all conditions.

Making the installation less daunting are step-by-step instructions that guide you through the process. You don’t have to piece together mismatched components or worry about plumbing and wiring, as Holley’s kit handles it all. The combination of performance, ease of install, and OEM-like appearance makes this a solid upgrade for anyone restoring, modifying, or building a Fox Mustang for street or track use.