Many years ago, we brought this kit to market as the first complete bolt-on RSK (Reverse Shackle Kit) for 1992–1997 OBS (Old Body Style) F-250 and F-350 4x4 trucks that required no frame or bumper modifications. In our continued pursuit of delivering industry-leading, well-engineered components, we have once again raised the bar with the market’s first 3-piece RSK system.
As has been the case from the beginning, we worked closely with our customers and listened to their needs and challenges. This new design was driven by the inconsistencies and loose manufacturing tolerances commonly found on these older trucks. The result is a system with maximum adjustability, ensuring a smooth and straightforward installation while maintaining exceptional strength and durability.
This kit utilizes existing holes in the frame and clears all factory bumper mounts and components. For customers planning to install an intercooler, the kit has been engineered with optional bolt locations to provide additional clearance for most intercooler end tanks. In this configuration, two additional 1/2" holes per side will need to be drilled.
The improved geometry of our RSK provides a noticeable improvement in ride quality. By relocating the shackle to the rear, impact forces are allowed to travel naturally through the rear of the leaf spring and into the new shackle position, resulting in a smoother, more controlled ride.
This system is designed for use with either the factory OBS leaf springs or the newer 1999–2004 Super Duty leaf springs. For optimal ride quality, we strongly recommend using the longer Super Duty springs. These springs offer increased length and improved spring rates, allowing for greater suspension travel and a softer, more compliant ride. Selecting the incorrect leaf option will result in improper fitment and function.
The kit is available in three different lift heights, which represent the lift provided by the RSK itself. Please note that additional lift may be gained depending on the specific spring code used. The kit includes front hangers, rear shackles, and all necessary hardware to mount these components to the frame. Leaf spring eye bolts and U-bolts are not included but are available for purchase separately if needed.
The kit includes a standard 3/16" crossbar. When upgrading to Tow Hook Rings or a Receiver Hitch, the crossbar is automatically upgraded to a 1/4" thickness.
Please select the correct axle configuration for your application. This kit is compatible with either the OBS Dana 60 solid front axle found in 1985-97 F-350 trucks or the 1999–2004 F-250/350 Super Duty Dana 60 axle. These configurations are not interchangeable. Selecting the incorrect axle option will result in improper fitment and function.
THIS KIT IS DESIGNED TO WORK WITH A 4x4 BOXED FRAME RAIL. IF YOU HAVE AN OPEN FRAME RAIL, YOU WILL NEED TO PURCHASE OUR "FRONT FRAME RAIL BOX KIT" SOLD SEPARATELY
THESE WILL REUSE THE OEM LEAF HANGER UNDER THE BODY MOUNT THAT COME ON THE 4X4 CHASSIS. IF THE TRUCK IS A 2WD, YOU WILL NEED TO SOURCE THE SHACKLE PIVOT BRACKETS OR PUCHASE OUR ADJUSTABLE POSITIN REPLACEMENTS IN ADDITION TO THIS KIT.
THESE KITS ARE CUSTOM BUILT TO ORDER AND TYPICALLY SHIP IN ONLY 1-2 WEEKS!
YOU MUST USE OEM LEAF SPRINGS OR SPRINGS THAT ARE BUILT TO THE EXACT SPRING EYELET TO EYELET LENGTH AS AN OEM LEAF SPRING!! OBS ARE 52" AND SUPERDUTY ARE 55 1/2" EYE TO EYE!! SOME AFTERMARKET LEAF SPRINGS ARE MADE TO SHORTER MEASUREMENTS WHICH WILL CAUSE ISSUES WITH AXLE PLACEMENT AND SHACKLE GEOMETRY. PRO COMP LEAF SPRINGS ARE PARTICULARLY PRONE TO THIS ISSUE!!
