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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®"

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 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 222 | Next

  1. Smoother and quieter 5 Star Review

    Posted by on Apr 29th 2018

    Little tough getting to the plugs to get out but that’s not a riff raff issue. Just unbolted the a/c compressor and moved aside. I went with the black spring. Why did I wait so long to do this mod?

  2. Nice piece 5 Star Review

    Posted by on Apr 26th 2018

    Trucks idle is rock solid. An dont let the install intimedate you it wasnt bad at all on my 2001F350.
    Feel it alot at idle, but i believe it helped support higher rpm runs too. As my truck lives a little more above 3K than i guess it should. But drive it like you stole it!! Cant go wrong with this FRx fit is nice an its operated flawlessly. Just watch for abrasion points. Some loom or jacket is a nice piece of mind during install.

  3. Like a charm 5 Star Review

    Posted by on Apr 24th 2018

    Goes on flawlessly with the motor out of truck haven't go to see if it made a difference in the truck due to motor still out. Fits perfect and looks good

  4. quality product 5 Star Review

    Posted by on Apr 23rd 2018

    installed the frx with the gold spring. its a great product, really quality made. The fittings are a serious pain to get started in the heads but its not a riff raff product problem. I didn't notice any quieter running. the motor is noticeably smoother which in essence makes it seem quieter. Throttle response is crisp. I did the hpx a couple weeks ago just to be able to see a difference. I highly recommend the hpx to correspond with the frx. Still have cvd fittings and banjo bolts to install before the fuel upgrade is complete.

  5. High quality part 5 Star Review

    Posted by on Apr 17th 2018

    Installed this with the HPx and the truck runs smoother and quieter now. Great job by Riffraff on the design and manufacture of quality parts to upgrade my powerstroke.

  6. Great upgrade for the price 5 Star Review

    Posted by on Apr 15th 2018

    Installed along with the HPX, both noticeably quieted engine down and smoothed up at idle.

  7. Great products as always 5 Star Review

    Posted by on Apr 15th 2018

    All around great product

  8. fuel cross over 5 Star Review

    Posted by on Apr 12th 2018

    Was worth the money the truck is 13d quieter in truck cab thats one of the reasons i bought it havent had on the truck long enough to see any other improvments

  9. best money spent. 5 Star Review

    Posted by on Apr 5th 2018

    A previous owner of my X jury rigged a fuel pressure regulator together and it always made me nervous it would blow apart. Well one day while topping off fluids I noticed diesel pumping through the gauge and I thought that's not right. A quick plug and an order into Riffraff. I ordered a bunch of upgrades I had been ogling. Clay was a champ as usual and answered all of my questions and concerns. This unit quieted down the engine, it looks great and it was fairly easy to install. if you are hesitating, wait no longer. It is a great upgrade and piece of mind.

  10. Bought to improve repair times / less cranking during fuel drains 5 Star Review

    Posted by on Apr 5th 2018

    Found this is excelent for getting air out of the fuel system and priming without cranking after engine work.

Showing reviews 1-10 of 222 | Next