Fuel Rail Crossover™ (FRx)

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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.


1999-2003 7.3L Powerstroke with stock fuel bowl
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  • 5
    Regulated Fuel Return

    Posted by Paul on May 10th 2024

    Hands down one of the best mods I have ever done on my Powerstroke. Easy install, and super clean once installed. Truck runs smoother and quieter than ever.

  • 5
    FRX crossover

    Posted by Chad Hanson on May 3rd 2024

    Nice product installation a breeze quality product Happy with purchase

  • 5
    7.3 fuel rail cross over lines

    Posted by JAY on Apr 29th 2024

    Oh man! Great! Simple, no leaks and seems to run better, no issues at all!!

  • 5
    if your thinking about it do it

    Posted by connor kelly on Apr 5th 2024

    I did this and the hpx at the same time can't say which one made more of a difference. But they removed most if not all the shake from the motor. Along with some of the noise from the injectors it idles smoother its almost like I put a different motor in the truck.

  • 5
    Awesome product

    Posted by James D on Apr 2nd 2024

    Finally got The FRX and Stainless Steel Lines installed along with a T-800 from Joey. Have to say everything fit perfectly and has made quite a difference in the overall drivability of the truck. Im using the Gold Spring but still holding 70psi fuel pressure. Riff Raff makes some amazing products.

  • 5
    No more injector knock!

    Posted by Micah M on Mar 28th 2024

    My van idles so much smoother! I installed this and the HPX and my engine is loving it. Knocking noise from the injectors at idle is so much quieter, if even there at all. 1000% recommended.

  • 5
    Worth it

    Posted by John Smith on Mar 19th 2024

    Wow... I'm a bit more impressed than I thought I'd be. My only qualm is the square socket that comes with it is 9/32 when it should actually be 10/32 (5/16). The fitment will only work with a 5/16. Truck is noticably quieter and I can actually hear my music using a lower volume now. The truck just sounds "healthier" and "cleaner"... also the clacking sound from the last injectors is 80% quieter... Definitely should be one of those mandatory upgrades. Also could just be me but I feel my acceleration has improved slightly as well. Next thing on the list is the HPox now. Equally as excited for that one.

  • 5

    Posted by LAWRENCE KELLY on Mar 5th 2024

    Really innovative awesome product..truck is lovin these RiffRaff mods.

  • 5
    Fuel rail crossover

    Posted by Ryan on Feb 1st 2024

    Great kit easy install