2005-2025 Superduty 4.5-5.5" Dual Rate Coil Springs (KRFC45)

After years of testing, from daily driving to harsh off road terrain, heavy hauling and everything in between, the Kryptonite 4.5"/5.5" Dual Rate Lift Coil Spring set is now available. This is the most durable and premium spring option on the market. Designed with heavy duty truck use in mind, this spring provides rugged load handling capabilities while maintaining an extremely comfortable ride. Using top rated materials we can produce a plush ride with minimal spring sag. Our true Dual Rate Spring can truly provide the best of both worlds. Mile after mile our springs will hold up to any truck, and any job. Installing these coils on a gas Super Duty will result in a VERY stiff ride. We DO NOT recommend this whatsoever.

• 4.5" of Lift 2005-2019, 5.5" of Lift 2020+
• Multi-Rate Spring, Designed for the 6.7L Powerstroke
• Powder Coated Black Finish
• Shot Peened for Durability
• Improved Strength and Rigidity over OEM
• Direct Fit Install
• Made in the USA