Fuel Rail Crossover™ (FRx)

Part Number:
FRx

Manufacturer:

$209.13
$197.88
(You save $11.25 )

7.3L Diesel Fuel Rail Crossover™ (FRx) 99-03 Powerstroke

"The Prescription For Your Fuel System Needs®"

Our 2nd Generation FRx™ System utilizes Eaton Aeroquip® 304 Stainless Steel Braided lines covered with a groundbreaking protective layer of HYTREL® from DuPont.

The FRx™ was made to solve the 'deadhead' fuel rail issue on the 99-03 Powerstroke engine by connecting the two heads and allowing a metered return you allow the air another return path, rather than forcing it through your injectors. This product was designed to eliminate the need to cut your return line and use compression fittings, so that it is a true bolt on system. We have also machined the FRx™ block to provide from stock to 72 psi of fuel pressure depending on which spring you choose to install it with. By using our kit and eliminating the air in the fuel system you can experience smoother, quieter idle, less cackle, and better throttle response among other things. You will also be increasing your injector life as well by utilizing the FRx™ and creating a regulated return back to the tank. Protective covers are also pre-installed to prevent chaffing of engine components from the SS braided line. These covers are also great if you want to keep the system looking OE and not draw attention to it once installed.

Included:                                                                                        Techical Info:
- FRx™ System                                                                               - Exceeds SAE 100R14A
- 3 Springs for adjusting Fuel Pressure                                              - Rated for commercially produced B100
- Viton O-ring                                                                                  - Temperature Rated -100˚F to +450˚F
- Parker® Fuel Sleeve                                                                      - Max. Working Pressure 3000 psi
- 2 Stainless mounting bolts                                                             - Minimum Burst Pressure 12000 psi
- Custom 9/32" socket

Fuel pressure spring settings 
55-60 psi  silver spring
61-65 psi  gold spring *Recommended 
66-72 psi  black spring

Riffraff Diesel Performance is committed to 100% Made in the USA. All materials are from USA resources. Every machining step is performed in the USA. Every component is assembled in the USA.

install.jpg

1999-2003 7.3L Powerstroke with stock fuel bowl
Write a Review

414 Reviews Hide Reviews Show Reviews

  • 5
    FRX

    Posted by Brett on Feb 2nd 2026

    Easy enough install if you watch the provided video. I installed while replacing fuel bowl seals/o-rings so y fuel bowl was out of the way which probably made the install a bit easier. I do think it quiets down the 7.3 inside the cab of Excursion. Unsure of any mpg gains but I was averaging over 16mpg on recent, 1,000+ mile, road trip after install.

  • 5
    Another great RDP product

    Posted by Robert Naef on Jan 31st 2026

    Super reasonable price for an extremely high quality product! The attention to detail and craftsmanship that goes into RDP products is very evident. Some complex cnc programing, great surface finishes and deburring, high quality coating, laser or cnc engraving, plus it works wonders and is a great simple and very affordable solution/improvement for the 7.3 fuel system. Riffraff does not cut corners.

  • 5
    100k mile review

    Posted by Michael on Jan 17th 2026

    I put this on and it has made a big diffrence in the performance of the engine. It smothed out the idle and it seems to have made a diffrence on cold starts, though i cant prove that i feel like since installing it, its started quicker in 0-15 degree weather. Was very easy to install in my openion.

  • 5
    Frx fuel regulated return

    Posted by Karl Johnson on Dec 30th 2025

    I installed this regulated return hoping that the many positive reviews I read were correct. After logging over 5000 miles since installation I can report that the great reviews were indeed accurate. This is such a huge improvement for the 7.3! Smoother and much quieter now. Especially nice when on long highway drives. This is a must have item for any 7.3 owner! Thank you Riffraff !!! This should have been standard from the factory

  • 5
    Fuel rail crossover

    Posted by Mike on Dec 26th 2025

    Wow, truck sounds quieter and runs smoother! No fuel knock anymore!

  • 5
    Mandatory 7.3 mod

    Posted by Blake on Oct 1st 2025

    Injectors sound a lot quieter, and my 120hp tune is usable now. Truck used to run out of fuel after 2,500rpm but now it pulls hard throughout the whole rpm range. 10/10 would buy again.

  • 5
    Improved fuel flow

    Posted by Monica Rey on Sep 25th 2025

    I noticed an immediate improvement in fuel pressure and engine response after installing it. Very good quality and easy to install. Worth every penny.

  • 5
    FRX Kit

    Posted by Unknown on Aug 6th 2025

    Straight forward install, and even my wife noticed how much quieter the truck is now. Quality kit, and I have no idea why Ford didn't just do this from the start.

  • 5
    FXR

    Posted by Eddie M on Jun 22nd 2025

    Easy to install, great quality and quieted the truck down a bit!