James Duff 70/30 Auto Adjust Shocks

A shock is a hydraulic tension dampener, used on vehicle suspensions to control spring rebound. SPRINGS COMPRESS... SHOCKS CONTROL REBOUND! Conventional 50/50 valved shocks use equal pressure on both compression and rebound sides. That creates a choppy ride, overheating shocks as they try to control compression instead of letting the spring do its job. Unhappy with the choices available, we tuned our own AUTO ADJUST SHOCKS for Ford's coil spring suspensions. Our shocks are valved 70% rebound, 30% compression. With our suspension systems, the coils are engineered so the shocks aren't needed for compression control. Our shocks smooth out the ride by controlling rebound.

Cellular foam keeps the fluid inside the shock from aerating as it does in cheaper hydraulic shocks. Aeration is what causes fading and poor performance. The combination of 10-stage auto speed adjusting valves with the all weather, multi viscosity fluid enables these shocks to maintain the consistent performance level we demand for on and off-road driving. For ultimate suspension tuning, properly valved shocks are a MUST.

High quality construction,built to last.Limited lifetime warranty to original purchaser. See full warranty in back of catalog.

We will be happy to consult with you to determine which shocks will properly fit your vehicle.
#8108 to 8116 70/30 Auto Adjust Shock $36.00
Shock Boot w/Shock, $2.00
#8900 Blue Shock Boot also sold separately$4.50

•Twin Tube Construction
•Foam Cell in a 2 3/8” Reserve Tube
•1 3/8” High Temperature Iron Piston
•Double Welded Ends
•5/8” Hardened,Chromed Piston Rod
•Corrosion Resistant Baked White Finish
•Blue Polyurethane End Bushings
•10 Stage Auto Speed Adjusting
•30%Compression, 70%Rebound
•Multi Viscosity, All Weather Fluid
•Internal Urethane Bumpstop

Long Travel Shock

The same great design and quality construction as our other shocks, with added features for long travel and high articulation suspensions. The first of these features is length. Our 8120 is 35 1/2" extended and 20 1/2" collapsed. With 15" of vertical travel, this is the longest shock available in this style. It would take going to an expensive racing shock system to get this kind of travel.
They also include a larger narrower eye loop, utilizing an extremely flexible rubber bushing with thick shoulders. The result is a bushing that will twist as much as possible in all directions while still maintaining its anti-vibration characteristics and durability. This eye design has twice the articulation of the standard eye design with an hourglass bushing. Shock mount flexibility is important because without it the shock will bind, limiting suspension travel. These shocks not only work great crawling over trails at 6 hours per mile, but also at 60 miles per hour over freeways, washboards and sand dunes.
#8120 70/30 Auto Adjust Long Travel Shock, $45.00

Progressive Rate Coil Springs
We've taken our decades of experience in Early Bronco suspensions and produced our progressive rate coil springs to be the best available, period! Several independent tests by Bronco owners have shown our springs not only provide a higher degree of ride quality, but out travel and outlast any other coil on the market. We realize that every Bronco owner uses their vehicle in a different way.We addressed this by creating a four stage progressive rate spring that provides excellent on road ride and handling, as well as jaw dropping suspension travel that lasts. Having a spring that lasts is extremely important since most people don't want to be buying springs every couple years. We use our own proprietary version of spring steel to provide a spring that does not sag,even after thousands of miles of testing. Our progressive coil rate gradually increases as the coil compresses.The upper wraps are softer for a more comfortable street ride; the middle rates are a bit firmer to handle bumps and dips without jarring; and the last few wraps are a higher rate so that they control the up travel to prevent bottoming out. The progressive nature of the spring also allows for better and more predictable handling by helping keep the vehicle flatter in the corners and limiting body lean. Our Broncos are our daily drivers and our play vehicles. We've been there and done that, so you can rest assured that no matter what you want to do with your vehicle, our suspension will take you there and back in comfort. All coils are blue powder coated for durability and come with zinc plated upper coil retaining clips. NOTE: Due to the longer coil, a coil spring compressor may be needed in order to make installation easier on some vehicles.

#5107 3.5" Progressive Coil Spring, pair, $160.00
#5109 5.5" Coil Springs, $170.00

Stage 3 Tubular Long Travel Radius Arms
Ours are the only Early Bronco Radius Arms to utilize 2" diameter, 1/4" thick heavy wall tubing, cast iron head units, and massive 1" bore high quality Rod Ends for maximum strength. Arms are designed with built in caster, offset to clear larger tires and tight to the frame rail to improve ground clearance. 10 3/4" longer than stock—Moving the pivot point farther back vastly improving suspension travel and articulation, overall handling and control for on road driving. Built in lower shock mounts for use with stock shock mounting position or our Stage 2 Hoops and our Long Travel Shocks for 15" of travel. Best results are achieved when these arms are used in conjunction with Duff suspension components. Blue powdercoated for long lasting good looks. Requires reuse of original C-caps. Includes arms, head units, rod ends, bushings and all necessary mounting hardware. All new parts, no core necessary.
#5350 Stage 3 Tubular Radius Arms, 1966-77 Bronco, $699.00

To get maximum travel, these arms are designed to be used with Duff engineered Components!
Results may vary with other components.

Leaf Shims
Improper pinion angle can lead to driveline vibration and premature u-joint & cv-joint failure. Not all 3 1/2” lifts will require a pinion adjustment but going up to 5 1/2” will result in a driveline angle that will need corrected. These steel shims bolt on to the bottom of your leaf packs. To determine the proper amount we recommend taking measurements before and after installing your suspension. The optimum angle is 2°. For more measuring info, please call.


#5542 2° Leaf Shim Kit, $49.00
#5544 4° Leaf Shim Kit, $49.00
#5546 6° Leaf Shim Kit, $49.00

Radius Arm C-Caps

Exact reproductions of stock caps, cast of ductile steel. Combine with our Radius Arms and Axle Wedges and you can put a Dana 44 or 60 under just about anything! Come bare.

#5341 Radius Arm C-Caps, pair, $85.00

Adjustable Radius Arm Drop Bracket
Lifting causes a loss in caster, causing wandering and loose steering. With this state-of-the-art adjustable drop bracket, you can reclaim that lost caster and have great handling again. We offer our urethane "C" bushings in 4° & 6.25°, but that may not be enough adjustment for your vehicle. If you have already installed new "C" bushings, it allows you to correct for the ad-ditional amount of caster you may need; 1°, 2°, or 4°. Gold Zinc plated for long life and good looks. Mounts using our urethane strut bushings, #6100 (sold separately). Cutting & welding are required for installation. Dropping auxiliary gas tank is necessary for installation.

11 Leaf Springs
These springs are designed the same as our 10 leafs with added weight capacity for a hard top, tire carrier, or rear passengers on a regular basis. With these springs, ride and articulation are not hampered in order to handle the extra weight. These leafs work great for handling the extra load of heavy bumpers combined with all the necessary tools and spare parts that go along with trail use.

#5570 3 1/2" Lift Heavy Duty, pair, $459.00
#5580 3 1/2" Lift - Medium Duty, pair, $459.00
#5585 5 1/2" Lift Medium Duty, pair, $459.00
#5570 3 1/2" Lift Heavy Duty, pair, $459.00

Long Add-a-Leaf for 10 Leaf Springs
If you bought the 10 leaf packs and then added more weight or your vehicle is heavier than you thought, this add-a-leaf will help handle the extra weight. Unlike most short add-a-leafs this full length spring does not sacrifice articulation for the sake of maintaining spring arch. These leafs are tapered and come with Teflon wear pads and replacement center bolts. Not for use in stock height or worn out springs. Inspect your leaf springs for sagging, cracks or daylight between leafs before ordering. Add-a-leafs will not make up for tired or cracked leafs. Upgrading to a new leaf spring pack may be necessary.
#5556 Long Add-a-Leafs for
2" 10 Leaf Packs, $79.00