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Riffraff Diesel Performance Inc, Engines - Supplies, Equipment & Parts, Eagle Point, OR


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Fuel Rail Crossover™ (FRx)

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Your Price:
$188.81 (You save $8.56)
Part Number:

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

"The Prescription For Your Fuel System Needs®"

We are now shipping our 2nd Generation FRx System that 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 will 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.


- FRx System
- 3 Springs for adjusting Fuel Pressure 
- Viton O-ring 
- Parker® Fuel Sleeve
- 2 mounting bolts
- Instructions

Techical Info:
- Exceeds SAE 100R14A
- Rated for commercially produced B100
- Temperature Rated -100˚F to +450˚F
- Max. Working Pressure 3000 psi
- Minimum Burst Pressure 12000 psi

Fuel pressure spring settings 

55-60 psi  silver spring
61-65 psi  gold spring
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.


Product Videos

How To: Riffraff Diesel Fuel Rail Crossover (FRx) (04:01)
How to install the Riffraff Diesel Fuel Rail Crossover (FRx) on your 7.3 powerstroke. Purchase: http://www.riffraffdiesel.com/fuel-rail-crossover-frx/ PDF Instructions: http://www.riffraffdiesel.com/content/RESOURCES/Riffraff_Diesel_FRx_Instructions.pdf
  • How To: Riffra...
    How to install the Riffraff Diesel Fuel Rail Crossover (FRx) o...
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Product Reviews

Showing reviews 1-10 of 148 | Next

  1. Frx to solve your fueling issues 4 Star Review

    Posted by on Sep 20th 2016

    Overall ease of installation, instead of unbolting the fuel
    Bowl I found it easier to disconnect both lines off the bowl itself. Biggest issue I had was getting be fitting into the driver side head, extremely tight fitting area. If you want true increased throttle response, and overall better running engine buy the Frx. Installed the recommend spring and you'll be golden.

  2. Great Product - Worth the effort 5 Star Review

    Posted by on Sep 4th 2016

    This is a very well made product. The instructions are well written and easy to follow. The installation can be challenging, but only because the ports may be difficult to get to. Once the pipe plugs are out, it goes pretty smoothly. The results are definitely worth it. The engine idles much more smoothly. Note that I also installed the oil crossover at the same time, so it's difficult to know how much each device contributes to the end result - but taken as a whole, it was worth the money, time, and effort.

  3. Works Great 5 Star Review

    Posted by on Aug 30th 2016

    Definitely less noise at start up and a smoother idle. I would have liked to see a little more information on the different spring choices that come with it.
    Thanks Guys

  4. Awesome Product 5 Star Review

    Posted by on Aug 19th 2016

    FRX is awesome. Not sure what Ford was thinking by not making this a standard product, but thanks to Riff Raff for bailing them out again.

  5. READ THIS 5 Star Review

    Posted by on Aug 8th 2016

    This should be sold as a kit with the CVD fittings and banjo bolts. I didn't find out about this until after I got my truck running and the injectors were making a bunch of weird noise from air in the system. If you're getting into your fuel system, BUY ALL 3 AND PUT THEM IN!!!
    It's amazing how hot the return line is even near the tank, that means it's working!

  6. Fuel rail crossover 5 Star Review

    Posted by on Aug 5th 2016

    Great product, less noise, smoother idle, simple to install. Thanks to Riffraff for super service and to Clay for his help and information for a first time powerstroke injector job.

  7. Awesome Product 5 Star Review

    Posted by on Jul 20th 2016

    What a great product, easy install, much less then others on the market. You can tell they really put some engineering into this thing. Really made the truck quieter and I am consistently getting 2mpg better. Home rune Guys!

  8. well designed, quality product! 5 Star Review

    Posted by on Jul 20th 2016

    The FRX is much simpler than many other regulated fuel returns, yet still accomplishes the same thing. Install was super easy with great instructions. Truck really smoothed out and seems to fuel a little harder all the way through the range. Great product with great service, I've got the HPX as well, next is the billet wheel and high flow fittings! Clay is the best in the business!

  9. Better fuel mileage 5 Star Review

    Posted by on Jul 11th 2016

    I bought this product, installed it before my road trip and my fuel mileage went up!

  10. too easy to pass up 5 Star Review

    Posted by on Jul 8th 2016

    Just got this FRX this afternoon, read over the instructions and went for it. Take the ac compressor and stand off for super easy access on the front. took maybe 1 hour. cycled key a few times and vvrrroooom. sounds great [quieter and smoother]. took care of a long-crank issue I was dealing with also. Great bang for my buck. Cant wait to order more RIFFRAFF stuff, Im hooked. ERIC A.

Showing reviews 1-10 of 148 | Next