Product Code: 5355-Config

T-Rex Stock Length Radius Arms, 1978-79 Bronco F150 4WD Kit Configuration

From: $999.95

(21 customer reviews)

Contents

Includes:

  • 1 Driver and 1 Passenger Arm
  • 2 Headunits
  • Installation Hardware
  • Instructions

Information

NOTE: THESE ARE CURRENTLY ON AN 8-WEEK LEAD TIME

Our new T-Rex radius arms are a stock-length version of our heavy-duty long arms with a built-in offset for additional tire clearance but unlike the extended arms, these are a direct bolt into your existing frame brackets. They use stock-style polyurethane bushings, no welding of new brackets is necessary. Yes, 100% bolt-on! Why would we do such a thing? Many Bronco owners want an arm that can clear a larger tire when turning without having to grind, drill or weld on their frame.

These arms work for stock height Broncos and up to 3.5" of suspension lift. The arms come with 4.25° of caster built-in. Shock mounting is different than our extended arms, these utilize a single shock mount located on top of the arm for a tighter turning radius arm, similar to a stock arm. Come powder coated in Signature Duff Blue or upgrade to new Midnight Black Metallic.

Features

  • Made in the USA
  • 100% Bolt-in, No Welding Required
  • Improves ride and handling
  • Run up to 37" Tire without rubbing radius arms
  • Eliminate unsafe and rusty stock radius arms
  • Best radius arm on the market for street and trail use
  • Already comes powder-coated black or blue, all hardware included

FAQ

Q: Are these compatible with Long Tube Headers?
A: These are only compatible with Duff Long Tube Headers produced after 2002. Other manufacture's long tube headers will make contact with the arm.

Q: Will these work on stock-height Broncos? 
A: Yes, they work great from 0-2.5" of lift. 3.5" or more of lift may require installing drop brackets to get the caster correctly set.

Q: My arms didn't come with the c-cap, are these included?
A:
 No C-Caps are not included, if your Bronco doesn't have these already you can purchase them at the same time, color-matched to your arms, they are also available here.

Q: Are T-Rex arms included in any of your lift systems?
A:
 Yes you can find these in our DuckTuff 2.5" Performance Package, our Ultimate Plus 3.5" and our Dual Sport Monster High-Performance Suspension system.

Q: Can I reuse the factory-equipped sway bar after installing these?
A:
No, it is not compatible with factory sway bars. For Early Broncos, we offer our dual sport sway bar system. Big Broncos will need to remove their sway bar.

Q: Are these compatible if my Bronco came equipped with dual shocks?
A:
You will need to either re-use your factory c-cap that has the cast factory mount or purchase new c-caps and weld in our c-cap mount. If you have dual shocks mounted behind the coil spring, you will only be able to use one shock.

Check out our other FAQs here.

Compatibility

  • 1966 Bronco
  • 1967 Bronco
  • 1968 Bronco
  • 1969 Bronco
  • 1970 Bronco
  • 1971 Bronco
  • 1972 Bronco
  • 1973 Bronco
  • 1974 Bronco
  • 1975 Bronco
  • 1976 Bronco
  • 1977 Bronco
  • 1978 Bronco
  • 1979 Bronco

 

  • 1976 F-150 4x4
  • 1977 F-150 4x4
  • 1978 F-150 4x4
  • 1979 F-150 4x4
Installation Note:
Installation Note:

Factory sway bars from the Early Bronco, Big Bronco (1978-79), and F-Series trucks must be removed to use our T-Rex Radius Arms.

These are only compatible with Duff Long Tube Headers produced after 2002. They will not work with other Long Tube Headers.

21 reviews for T-Rex Stock Length Radius Arms, 1978-79 Bronco F150 4WD Kit Configuration

  1. Eric T (verified owner)

    These are stellar quality with solid powder coating. Added needed positive caster. The install videos made all the difference for me in deciding to purchase these and take on a DIY project.. This is one of the several Duff upgrade pieces that my alignment shop called very high-quality hardware. This shop does high volume work on mostly 4WD vehicles for a popular local custom tire/wheel business. Their experience is significant, and they spoke quite well of these TRex arms. Though I handled them by myself in my garage, the weight and shape were near my limit. I had my teenage son available now and then to lend a hand. Not mandatory but helpful.

  2. Richard Gutierrez

    I have these on my 66 with 3.5″ lift. They work awesome. I do 70% street and the rest offroad but nothing crazy. This kit is awesome with the duff heim steer. I had these arms with new old school tie rods
    It drove wonky. But incandescent admit the t-rex arms and Duff Heim steer are a great great combo. Getting a helping hand makes it a lot easier. Installing t rex arms and heim steer onan friends bronco. That’s how much I believe in Duff products.

  3. Marc Martin (verified owner)

    Great product. Very well made. Installation was pretty straight forward. Instructions were well detailed. My Bronco drove a lot better after installing these arms. Would highly recommend to anyone thinking about buying them, just do it.

  4. Chuck Meyer (verified owner)

    Haven’t driven with them yet, but the install was fairly easy. They are very heavy duty and just look cool. Duff’s staff were great in quickly answering my questions.

  5. Stan Massey

    I had the t-rex arms installed on my bronco, thinking my bronco drove good…I couldn’t believe the difference they made in the drive ability, like I was driving a whole different vehicle. 👍👍

  6. Sam Waller

    Still waiting to put these on. But if you have a bronco you know James Duff is the best. Customer service is awesome, these guys have the knowledge to get your rig setup to your needs.

  7. Jay Smith (verified owner)

    These radius arms are well constructed and fit very nicely. I don’t expect to decals to last very long though. One person can replace the stock bars, but I would recommend an extra pair of hands

  8. David Franko

    I just got done installing T-Rex arms, and have to say their awesome !!! Their high quality and improved my ride 100 percent over stock. I would highly recommend these arms for stock or lifted to 3.5 inch. I pick them up at James Duff and the staff was awesome, and my wife and I meet Ms. James Duffy, what a wonderful lady, we wish the other duff family members were their ,but that ok.

  9. Daniel Collins

    Installed these on my 1979 F150 4×4. I had never done radius arms before and I was overwhelmed at first with what could go wrong, but after watching the install video on Youtube and reading the instructions that came with the parts it all went on like a dream! The video on their YouTube channel was an amazing bit of help, I went back to it multiple times just to double and triple check my work.

    I have since recommended James Duff T-Rex radius arms to multiple offroading Facebook groups and friends. My brother already ordered a pair.

  10. Kelly Belgarde

    These Radius Arms are simply the best aftermarket arms you can buy, in my opinion. They fit right, work right, and with the Duff blue arms and blue C-bushings, they L@@K AWESOME on my midnight blue “SHEBUX” Bronco. Every time I take it out to cruise night, I get people crowding (and drooling) over my truck. Simply OUTSTANDING!!! Thanks DUFF!!!

  11. Nate Huff

    The quality, fit and finish of the T-Rex arms is amazing. These solve SO many issues that are encountered when lifting an early Bronco (including improved caster, and improved turning radius). These are a game changer.

  12. Timothy Bjork

    when the time came to do the axle rebuild what better time to put a new arm that not only clears the 35inch tires I’m going to run but also increase flex and style. everything went together well, nice and snug.

  13. Charles McCutcheon

    These are awesome! Fit and finish is excellent. Installed a set for a small lift bronco using 33" tires, plenty of room, no tire rubbing!

  14. michael haagen

    Shipping was spot own! The t-rex arms look really good under my bronco. The frontend sets under the bronco better. I think this will be money well spent.

  15. Bryan Murphy

    They work great. No more rubbing

  16. Anthony Parigi

    James Duff Inc pulled through once again with a great product and outstanding customer service!

  17. Michael Sickels

    I was finally able to put tires on my rig after a 4 year build. I went with 35” tires thinking I would have enough clearance. First turn and my tires were rubbing on my stock radius arms. After a little research, talking with Tom Hyde and watching a great video with Jonathan Melton and Michael Duff I ordered my new arms. They bolted on without any modifications or issues. They look awesome. Way better looking than the weak stock arms and now I can turn without problems!! Thanks!! Not only do the look better but when I get it out on the trail I am sure my rig will perform better.

    Great product and a great company!!

  18. The IRON CASKET, Vigilante Racing

    These radius arms are one of the best upgrades I made!! They maintain stock locations but allow more travel and unmatched durability! I have several duff tuff parts on my racer and could not be happier with the performance. Vigilante Racing’s latest accomplishment was a 2nd place finish at the Wild West 100 in Columbus, Mt. 9/21/19. Thanks to James Duff we had another successful season. I would certainly purchase the Trex arms again!!!

  19. Tom Hyde CEO Lick Creek Restorations, LLC

    These arms are exactly what every factory 3 link Ford needs, specially if you add any lift or larger tires. We worked with Duff to develop this, ok I begged them to make a set out of their long arms for a build I was doing and they did. Little did we know all of the benefits they would yield. These are one of those items you just scratch your head and wonder why it took so long to come to market because you wouldn’t think they had much to offer besides a little more tire clearance on tight turns. Be prepared to have your mind blown when you put these little gems on. Be prepared to bask in the same amazement everyone else now gets to enjoy when they make the switch. They improve ride quality by reducing a pivot bind, this allows the springs and shocks to fully work as they were intended freeing up the ride, smoothing out the road and giving you handling characteristics like never before! These are now a standard part on all of our builds.

  20. Jonathan Melton

    The T-Rex arms really are and amazing product. Better street driving, more articulation off road, no welding, not cutting off the old radius arm hangars, these are awesome!

    If you can install C-Bushings, you can install these. They fit right where the stock Radius arms go. I wouldn’t say radius arms are “easy” to install, but they are worth it to install.

    Keep in mind, these won’t “solve” a bad driving Bronco, but they will definitely smooth out a stiff ride.

  21. Nelly K.

    I was extremely happy with the customer service from the Duff team. Love the thought on the brand and packaging that goes into the product. I’m a fan.

    Thanks!

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