T-Rex Evolution – Caster Adjustable Stock Length Radius Arms Configuration

Description

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 that are not designed to clear Duff radius arms, as the primary tubes cannot be routed directly beneath the Early Bronco frame.
The stainless brake line brackets #3670, only work on Early Bronco, standard width Dana 30/44’s

Contents

Includes:

1 Driver and 1 Passenger Arm
2 Headunits
Installation Hardware
Instructions

Replacement Parts:

Information

Our new Caster correcting T-Rex radius arms have arrived! This revolutionary new product is literally changing the game in Bronco suspension. This is 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 & have a cam bolt that can turn and adjust the caster to the exact amount desired on each arm independently. They use stock-style polyurethane bushings, and 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. Plus, caster is king when it comes to driving a Bronco, so having complete control over the amount of caster your Bronco has provides ultimate control for all suspension up to 6 inches!

These arms work for 66-’79 stock height Broncos and up to 6″ of suspension lift on 66-77 Broncos and up to 8″ of suspension lift on 78/79 Broncos & 66-79 F150 4×4’s. The arms come with 4.25° of caster built-in plus an additional 6.5° of cam bolt adjustability! Shock mounting is different from 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 Midnight Metallic Black.

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. They will not work with other long tube headers that are not designed to clear Duff radius arms, as the primary tubes cannot be routed directly beneath the Early Bronco frame.

Q: What C-Bushings should I be using for this new arm?
A: Great question, we have modified the suggestions from what we have traditionally used since this new design takes into account additional caster adjustment.

Early Bronco – T-Rex Radius Arms
1.5″ Lift: 2° C Bushings
2.5″ lift: 4° C Bushings
3.5″-5.5″ lift: 7° C Bushings

66-79 F150 4×4 & 78/79 Bronco – T-Rex Radius Arms
2-4″ lift: 2° C Bushings
5-6″ lift: 4° C Bushings
7-8″ lift: 7° C Bushings

Q: Will these work on stock-height Broncos?
A: Yes, these arms work for 66-79 stock height Broncos. Up to 6″ of suspension lift on ’66-’77 Broncos and up to 8″ of suspension lift on 78/79 Broncos.

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 these T-Rex Evolution arms included in any of your lift systems?
A: We will be including these in performance packages and other lift systems in the near future.

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. We do not offer an aftermarket sway bar for the Big Broncos and cannot provide any recommendations at this time

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