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 Stainless mounting bolts - Minimum Burst Pressure 12000 psi
- Custom 9/32" socket
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.
409 Reviews Hide Reviews Show Reviews
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Great!!
This crossover is not too difficult to install, but do be patient as installing the fittings in the heads is tight. The fuel block with spring is a bit of a challenge too, tight to install and keeping the o-ring and spring in place too. This is a modification Ford should have designed and installed at the factory.
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FRX
So far so good it has quieted down the single shot injectors, now just waiting on tuner to be re-flashed had a minor hiccup.
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Difference!
Installation takes a few hours due to the location of the test plugs and fuel lines. Used the included thread sealant and had no leaks on pressurizing the system. The contribution test now shows all injectors equal.
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Frx
You better have some time and beer! It took much longer than I expected. I had a hard time with the passenger side. The fitting threded into the block no problem but threading the frx on to the fitting really took some time. I had to step away and let my dad try for a while then I finally got it. The rest of the install was very easy. It works very well. The truck is much quieter. With this and the hpx it sounds like a different truck
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Beautifully Simplistic
What a great design. Seemingly simplistic but once you actually look close there is a lot going on in the machined billet block. Amazing quality, even the lines are awesome. Can’t go wrong with made in the USA parts.
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Fuel Rail Crossover
Installed at the same time as the HPOP crossover so I don’t know which made the difference. I recently install new Garrett GTPR Turbo and the installation of these 2 crossovers gave my SOTP Dyno as much satisfaction as I got from the Turbo installation.
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Frx
Quiets 7.3 injector cackle alot.
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Install and performance
Tricky for larger hands. Very noticeable improvement in injector response and performance.
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Money Well Spent
I installed Riff Raff Diesels' FRx and noticed a great difference in throttle response. Probably one of my favorite product to come from Riff Raff thus far!






