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

    Posted by Brandon on Mar 21st 2019

    Notable better throttle response and smoother idle

  • 5

    Posted by Sean H on Mar 9th 2019

    So much better, smoother and queiter. You can really tell the difference when you purge that air from the rails and push it to your fuel tank return rather than into your injectors.

  • 5
    Product is very quality and simple design.

    Posted by Justin on Mar 7th 2019

    Very good price compared to other fuel return system out there for the 7.3

  • 5
    Perfect Solution

    Posted by Randy on Feb 19th 2019

    This system is truly the perfect solution for the 7.3L and I have no idea why Ford didn't do this from the factory. These guys have taken the time to engineer this with great quality and it shows in the finished product. Love that it is made in America!

  • 5
    Very pleased

    Posted by Bill Meyer on Feb 12th 2019

    Fantastic product from riffraff once again. I have put a bunch of riffraff products on my late 99 7.3 in the last month and have not been disappointed with one thing or the customer service. I am new to the powerstroke world and Clay has been a huge help figuring out how to get the truck to be what I wanted. Excellent customer service, excellent products and great pricing. Pretty hard to top that. It would be pretty hard to tell how much difference this product made since I did several changes at once but can tell you it fit great and was an easy install. Directions say to use a vise grip or crescent to start the square 9/32nd plugs but I found that an open end 7mm fit perfect and made removal a breeze.

  • 5

    Posted by Don Packer on Jan 20th 2019

    Was having fueling issues, installed Bosch pump, FRX and HPX quiter injectors and more power

  • 5

    Posted by Jason on Jan 8th 2019

    Very easy to install and looks stealthy. Not sure if it is real or placebo but it seems to have helped smooth out some of the “clacking” under load.

  • 5
    Big Difference!

    Posted by Edgar Hinojosa on Jan 4th 2019

    Can't get enough of the quality from Riff Raff! Part looks great and everything fit well! Bumped up my fuel pressure, better performance and runs quieter!

  • 4
    Quality product

    Posted by Patrick Devine on Dec 16th 2018

    A few choice words some busted knuckles and 2 trips to the parts store I got the frx on and she’s running smoother than ever! Put a zip tie on the return line so the fitting can’t fall down the line like mine did..... pain in the *** but totally worth it