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 mounting bolts                                                                           - Minimum Burst Pressure 12000 psi

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
    Fuel Rail Crossover FRX

    Posted by Rick on Apr 30th 2021

    The FRX did exactly what it claims. Installed this on my 99 7.3 dually, all stock and no tunes. It runs noticeably smoother and bit quieter, and acceleration has a slightly improved. I'm very happy with this and would recommend

  • 5
    Worth Every Penny

    Posted by Paul R on Apr 29th 2021

    Does what everybody says it does. Idle is much smoother and acceleration is much more linear. Overall engine perceived noise is cut by half in my calibrated ear, ha! Seriously, noise is way down and number 8 injector banging is gone completely. even on a cold start. I did install the HPX and the brass poppet valve, seal and seat from the relief valve rebuild kit during the same mod-fest so it's hard to know what improved what but overall I'm very happy with this outcome. Well worth the time and effort. I will add a couple of tips. Order a spare FRx Replacement JIC/NPT Adapter with the FRx. Cheap insurance that won't pay for overnight shipping when you drop the rear one behind the engine like I did. And order the Fuel Pressure Relief Rebuild Kit. You'll want it when you see the worn out OEM plastic piece of crap poppet valve.

  • 5

    Posted by Taylor mckeel on Apr 21st 2021

    Really good product can definitely tell a difference in the throttle response

  • 5
    Must have !

    Posted by jacob kepner on Apr 20th 2021

    This was a pretty easy install, I would recommend removing the fuel bowl to make easy installation but not necessary that’s just the way I did it. I definitely noticed my engine noise has been reduced. All in all this is a great product and I would highly recommend it !

  • 5
    Works as should

    Posted by Tim M on Apr 14th 2021

    Not to difficult to install. Idle is smoother and throttle response is better. Marginal noise reduction. Would definitely recommend

  • 5

    Posted by Donnie L on Apr 14th 2021

    This work great i love it. I could not believe how much quitter the engine ran. Highly recommend.

  • 4
    Good product

    Posted by Mitch Yarger on Apr 11th 2021

    A little time consuming to install due to ford engineers . I does lower engine noise which makes quieter in the cab .

  • 5

    Posted by Jerry k on Apr 7th 2021

    Fittings made instalation a breeze, injectors didn't miss a beat due to air trapped in rails, noticeable improvement right away.

  • 5

    Posted by ChristDriven on Apr 6th 2021

    Definitely made truck run smoothly, noticeably at idle.