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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 145 | Next

  1. 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.

  2. 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!

  3. 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.

  4. 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!

  5. 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!

  6. 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!

  7. 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.

  8. Great Product 5 Star Review

    Posted by on Jul 5th 2016

    FYI, I had to take loose the AC compressor to get my tools/hand in to reach the front fitting.
    Not a big deal as I already had the belt and power steering pump bracket off to do the Riffraff Diesel High Flow Banjo Bolt.

  9. Excellent for any 7.3 Owner 5 Star Review

    Posted by on Jun 30th 2016

    What a difference this has made. Also did the oil rail crossover at same time. Really made a noticeable difference on quieting down the motor and much smoother idle. Also noticed that starting is much quicker and throttle response is way better as well. Do yourself a favor and get the 9/32 square socket from Clay at Riff Raff, its much easier than all the aggravation I went thru getting the plugs out. Other than that the rest of the install was pretty easy as I had most of the top of the motor apart with all the upgrades I did at same time.

  10. Huge difference in my 2000 7.3 5 Star Review

    Posted by on Jun 25th 2016

    First I want to make clear the difference this made in my truck was night and day when combined with a FASS. Now that we have that out of the way, get a friend, or child, with small hands to get the front fitting in. I don't know who made the video of putting this in but they left a lot on the cutting room floor. For one, I bought a socket after I ordered this kit to remove the pipe plugs. I can get the socket on but not a ratchet. I was able to use a small 1/4" drive 5/16 socket to get in there so all was good. To get the front fitting in, I had to get my 10 y/o son out there to put it in because there was no way my hand could get to it. Same when it came to put the fuel line on, he had to get it started for me.

    Worth the hassle but don't think for one second this is going to be a fast, or easy install.

Showing reviews 1-10 of 145 | Next