Rusty's FSJ 6" Full Size Spring Pack Lift Kit


  • Brand: Rusty's Off Road Products
  • Availability: In Stock
  • Part Number: RK-605SP-FS-RX1-316

Rusty's designed the FSJ 6" kit after getting many requests for more lift without doing a spring-over conversion. Rusty's used over 30 years of knowledge and the same technology we used on our successful 4" FSJ system to develop the Rusty's 6" suspension kit.

Some suspension companies claim nothing has improved in the manufacturing of leaf spring in 25 years. Well not at Rusty's! While other companies continue to offer an FSJ spring that was designed back in the 70's, many things have improved in the spring industry. Rusty's has incorporated many of these improvements in our FSJ springs, which are built in North America.

The 6" lift front springs are constructed with 5 leafs that feature tapered leafs ends and anti-friction pads for a smooth ride. The leafs are shot-peened to further reduce stress and increase spring life. Only the best in rubber bushings are used, and the Rusty's front springs have a 310lb spring rate.

The rear springs are a 6 leaf design with tapered leafs ends and anti-friction pads that reduce inter-leaf friction. Like the fronts, they are also shot-peened to reduce stress and increase spring life. Each spring is load-tested to ensure they meet the required specifications. The Rusty's rear springs have a 400 lbs. spring rate. Spring eye bushings and Grade 8 U-bolts round out the rear details. There is not a better front or rear spring pack built today.

The remainder of the kit consists of a complete set of 9/16" Grade 8 U-bolts, cast-iron 2.5" Fabricated steel tapered lift blocks, a drop pitman arm, and a complete set of Rusty's stainless steel brake line. Rusty's Hydro shocks are also included to provide excellent on- and off-road performance.


  • Best Quality Parts Built
  • Great Ride & Articulation
  • Complete Kit
  • Limited Lifetime Warranty

• 2 - 6" Front Leaf Springs
• 2 - 4" Rear Springs
• 2 - 2.5" fabricated steel tapered lift blocks
• 9 - Grade 8 U-Bolts*
• Braided Stainless Steel DOT Approved Brake Lines
• Drop Pitman Arm
• 4 - Rusty's Hydro Shocks
• Complete Instructions

*Note: We send an extra U-bolt with this kit. We have found that some models have two wide front differentials U-bolts and some don't. Rather than taking a chance of getting the wrong U-bolts, we send both. You will have one leftover.

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