Loading... Please wait...


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


  Our Newsletter

Fuel Rail Crossover™ (FRx)

  • Image 1
  • Image 2
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...
Write your own product review

Product Reviews

Showing reviews 1-10 of 230 | Next

  1. Yuge Difference! 5 Star Review

    Posted by on Sep 14th 2018

    Made big difference on how my truck started, and how quiet it is without all the air in the system. I should have done this years ago.

  2. A measurable improvement 5 Star Review

    Posted by on Aug 29th 2018

    FRx was installed during replacement of injectors and glow plugs. The idle is much smoother and quieter. Throttle response is improved, and I was able to eliminate the "cackle" injector. While my technician was performing the installation I did overhear a few expletives from under the hood. Once complete however, he was very impressed in the change and intends to recommend it to his other Powerstroke customers.
    I would like to add that the customer service is as good as the products they sell.

  3. This cured a noisy injector 5 Star Review

    Posted by on Aug 29th 2018

    I have had this installed about a month, my truck has a noisy injector when cold.
    This cured the noise in about a day.

  4. my 7.3 sounds so healthy now. 5 Star Review

    Posted by on Aug 27th 2018

    Got this with the HPX and my 7.3 sounds pretty happy now. Quiet and smooth!

  5. Smoother, quieter, & easier start 5 Star Review

    Posted by on Jul 27th 2018

    Just had this installed in my 2003 E-350. Definitely starts easier, quieter running, and feels smoother in general. Benefits of a regulated return at a fraction of the price.

  6. I like having the smoother running engine 5 Star Review

    Posted by on Jun 1st 2018

    I just got done upgrading my injectors, and with this RFX it was fast to bleed out the system and get the truck running again. It also seems to run a bit quieter and smoother.

  7. Perfect Upgrade 5 Star Review

    Posted by on May 31st 2018

    The RRD FR-X is a great way to upgrade your fuel system and get the benefits of a regulated return. The fit is perfect and easy to install.

  8. Theory makes sense 4 Star Review

    Posted by on May 27th 2018

    I like the theory that allowing air to find an alternate exit route other than the injectors will prolong the life of the injectors as presumably does the regulated 65psi.
    I have done all the standard mods separately and spaced apart to observe the results. The FRX has been the last and the biggest pain.
    The FRX hoses don't have swivel fittings which would be the cats meow when trying to connect the hoses to the fittings in the head. Don't let this project intimidate you though, just be patient. Review and follow the video and you will be fine. Here are some recommendations from my experience; 1. when you remove the EBP, clean the carbon and crud from it while it is out, 2. place a rag or paper towels below where the fittings install blocking their route to the ground or hiding places when you drop the fittings when installing, you won't have to look so far to retrieve them, 3. The supplied small rubber o-ring or washer goes on the fuel line you removed from the stock regulator, slide the nut back remove and discard the old one and replace with the new one. 4. before opening the thread sealant, squeeze and work back and forth the contents in case the sealant has separated.
    All and all I can't tell a difference in performance or sound, but I like and believe in the theory behind it. The biggest noted difference in sound (noise) came from the HPX (quality and easy install), and replacing the CVD's, I made my own fuel lines and used AN fitting where the CVD's go. I wish there were dyno and real performance and power results with each of these mods, instead of just sound and seat of the pants feel.

  9. 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?

  10. 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.

Showing reviews 1-10 of 230 | Next