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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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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. 

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.


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Product Reviews

Showing reviews 1-10 of 105 | Next

  1. Solid product 4 Star Review

    Posted by on Sep 18th 2015

    The quality and craftsmanship of the piece from RRD was exceptional. The installation of the regulator block to the fuel bowl was a cinch. However when it came to pulling the test plugs, they gave me some difficulty. For the front test plug, I ended up unbolting the A/C compressor and its bracket to give me room to remove the plug. I used a vice grip so I needed some wiggle room.

    The rear test plug came out pretty easy because I had the compressor housing off. To remove the rear test plug and attach the line and fitting would be very difficult without removing the housing. I hope this helps someone down the line.

    Performance wise, I've noticed a nice, smooth and tame idle with less cackle. With a press of the go pedal, there seems to be more smooth and constant power delivery throughout the rev range.

    Overall, I'm very happy with the product, but the install instructions could hint to the removal of those items I listed would make life easier!

  2. Great Product 5 Star Review

    Posted by on Sep 15th 2015

    easy install and works great! I immediately heard and felt a difference. Injectors make less noise and acceleration is smoother.

  3. Great Product and Price 5 Star Review

    Posted by on Aug 31st 2015

    I am very pleased with this product. I did this in conjunction with bellowed up pipes, ebpv delete pedestal, high flow outlet, and hpx. What a difference! It's like a have a new truck. The instructions don't say you have to take the turbo out, but you would need a child's hand to do it. I'm glad I was already doing the other work. I also had to take off the tensioner and compressor housing to get at the front bolt, but if you have small hands, you may be able to get it without. Overall great product, and noticeable difference in performance.

  4. almost perfect 4 Star Review

    Posted by on Jul 31st 2015

    I installed RfRf. FRX kit and instantly noticed the old 7.3 runnin smoother. the hardware and fitting seen to be very high quality and the job was easy. I do have one complaint,the short line jumping over to the right rail makes a slightly harsh bend around the new regulator block to that side. this is for anyone who is about to buy the FRX kit, I recommend buying the HPX kit at the same time, they work beautifully together!!!!

  5. Glad I did it 5 Star Review

    Posted by on Jul 27th 2015

    I replaced my injector O-rings, did the CVD fittings and the FRX at the same time. I used the recommended spring. It would be hard to say what exactly this would have done alone, but I'm happy with the overall. My truck starts faster, idles smoother, runs quieter and has more power with better throttle response. Quality seems excellent and I definitely recommend it.

  6. Good product hard install 5 Star Review

    Posted by on Jul 20th 2015

    Does everything everyone says my truck seems to spool up or accelerate a little faster. I love it but putting it in took 4 hours. Myself and another friend both mechanics fought it for a while but when toghter no leaks and all works as advertised.

  7. Much Quieter 5 Star Review

    Posted by on Jul 11th 2015

    Excellent product. Really does quiet and smooth out the engine. Install is not fun though, I recommend getting the special square socket, makes job easier.

  8. Good fit, well made:) 5 Star Review

    Posted by on Jul 10th 2015

    Another well made product from Riffraff, This is not where you want to go cheap, a poorly made product could easily turn into a big fire. I don't know if the mod really increases performance, but I like the idea of giving the diesel and air a place to go.

  9. Excellent product! 5 Star Review

    Posted by on Jul 9th 2015

    Fairly easy installation. Truck is more responsive and idles quieter.

  10. awesome 5 Star Review

    Posted by on Jul 8th 2015

    Great product! Easy installation

Showing reviews 1-10 of 105 | Next