Universal Drag Race H.D. Parallel 4-Link Rear Suspension Kit

• Parallel 4-link suspension system works with full frame or unibody vehicles
• Locates axle and prevents rotation/pinion angle change
• Requires a Panhard bar or Watts link system for total axle control
• Weld on 7 gauge brackets place tubular links in double shear mounting for strength
• Large 3/4-inch rod ends, and 1-inch steel link tubes easily handle high horsepower
• Multiple link points to square the rear axle, change instant center, and more
• Includes weld on upper shock mounts and adjustable bolt on lower mounts
• Works with coil spring or air spring mount kits or coilover shocks
• Can be installed inboard or outboard of frame rail as needed for clearance

Give Your Racecar a True Adjustable 4-Link Rear Suspension for Better Control

A “fixed” suspension with no adjustment is fine for street use and low horsepower applications. In most cases what the factory engineer designed for suspension pivot points, spring rates, pinion angle, and more are all a series of compromises in packaging and cost by the manufacturer. Trying to put 500 or more horsepower down on a dragstrip surface with drag radials or slicks is asking for major wheel hop or broken parts as leaf springs wrap up, triangulated four-links bind, and more. All these factory compromises do nothing for maintaining pinion angle and eliminating axle movement. Bolt on traction aids like traction bars help limit pinion angle changes but do nothing to change roll center or anti-squat. The only way to adjust these settings is with an adjustable rear suspension and one of the most popular options is a parallel four-link suspension setup.

The parallel four-link suspension is just as it sounds, four links (two upper and two lower) that are parallel to each other connecting the axle housing to the vehicle’s frame or unibody. The parallel 4-link suspension locates the rear axle assembly, centering it in the rear wheel opening, and prevents pinion axle changes during hard acceleration. Furthermore, the four-link suspension design allows squaring the axle in the chassis so that there is no deviation on the rear thrust angle, provides the user with the ability to adjust the instant center in relation to the car’s center of gravity (hint, a lot of math is involved). Making these changes also provides for changes in anti-squat, which further aids in tuning the 4-link rear suspension and chassis to the horsepower level, traction ability of the track surface and your rear tires, and more for the best launch possible.

Our Parallel Four-Link Suspension Works in Most Any Chassis Style

No matter if you’re looking to race a full frame pickup or a unibody muscle car like a Camaro or Mustang, our universal 4-link kit can be fitted to your ride. The frame brackets are made from 7 gauge steel for strength and are designed to be welded to any structural part of the frame or unibody (some vehicles may require additional reinforcement or a crossmember added for the correct placement of the frame brackets). The axle brackets feature a 3-inch radius to fit common 3-inch axle tubes, such as those found on the venerable Ford 9-inch axle housing. Both provide double shear mounting of the adjustable suspension links for strength. Adjustable rear shock mounts allow you to position the lower shock mount for the correct shock distance per your shock manufacturer. The 1-inch steel link bars use heavy duty 3/4-inch rod ends with left and right threads, allowing easy on vehicle adjustments for pinion angle and axle centering. We provide plenty of link mounting hole options to plot and set your suspension’s instant center and anti-squat for your horsepower level, track conditions, and more.

The parallel 4-link rear suspension ultimately controls axle location fore/aft and pinion angle, but you will need either a Panhard bar or Watts link to control lateral axle movement. While some four-link suspension setups use an angled track bar, these can flex under hard acceleration, we much prefer the Panhard bar or Watts link options, even though they can limit the use of full exhaust tailpipe routing to the rear of the car if you’re looking to retain a full exhaust system.

The adjustable shock mounts are designed for coilover shock use, but if you prefer to run a traditional spring, or even an adjustable ride height air spring kit, you can run a fixed or adjustable drag shock on these mounts as well.

Absolute Traction on The Track or Street Is Just an Adjustment Away

No other factory suspension provides the ability to adjust your vehicle’s traction capabilities like an adjustable parallel four-link suspension setup. Very few aftermarket rear suspensions offer this adjustment ability as many are focused on performance street use or road course ability. So, if you’re goal is to make it from point A to point B on a 1/4-mile (or 1/8-mile) dragstrip with the maximum traction available, you’ll want an adjustable parallel 4-link suspension like this. As track conditions change, tire temperatures change, or you add or take away horsepower in your tune, or weight in your chassis, having the ability to quickly make rear suspension link adjustments (along with shock tuning) will ensure your ride goes down the track straight as a string without any drama so you can focus on the win.

Kit Includes:

• Frame brackets
• Rear-axle brackets
• Upper and lower shock brackets
• 3/4” rod ends / 5/8" hole
• Jam nuts
• 14” threaded 1” O.D. tubes
• Bolts and washers

• Axle Bracket Height: 11-5/8"
• Axle Bracket Width: 4-1/16"
• Axle Bracket Thickness: .177"
• Frame Bracket Height: 11-5/8"
• Frame Bracket Width: 4-3/4" max
• Frame Bracket Thickness: .177"
• Max Assembled Length, Bracket-to-Bracket: 23-3/4"
• Shock mount hole size: 1/2”
• Shock mount max height adjustment above axle centerline: 4”
• Shock mount max height adjustment below axle centerline: 2”
• Height adjustment from axle centerline on upper mount holes: 5-25/32”
• Height adjustment from axle centerline on lower mount holes: 4-3/32”
• Axle tube diameter that brackets are notched for: 3”