Carli AP-FFSP-17 Full Progressive Leaf Spring 3" Lift for 17-25 Ford F250/F350

Vehicle Fitment

• 2017-2019 Ford F-250 Super Duty (4WD, 6.7L Power Stroke Diesel)
• 2017-2019 Ford F-350 Super Duty (4WD, 6.7L Power Stroke Diesel)
• 2020-2022 Ford F-250 Super Duty (4WD, 6.7L Power Stroke Diesel)
• 2020-2022 Ford F-350 Super Duty (4WD, 6.7L Power Stroke Diesel)
• 2023-2025 Ford F-250 Super Duty (4WD, 6.7L Power Stroke Diesel)
• 2023-2025 Ford F-350 Super Duty (4WD, 6.7L Power Stroke Diesel)

Fitment Notes

• 4WD diesel models only - does not fit 2WD trucks or gasoline models
• Fits trucks with 3.5"-4.0" diameter rear axle tube
• This is an individual leaf spring (sold individually) - order 2 for a complete rear set, or purchase the CS-FFSP-17 kit which includes both springs, U-bolts, bump stop drops, and hardware
• 3" rear lift designed to provide a 1" rear-high stance when paired with Carli 4.5" and 5.5" front suspension systems
• Carli Full Replacement Leaf Springs are designed to work with Carli custom-valved shocks - they do not work well with off-the-shelf shock valving
• Block-eliminating design - removes factory lift blocks
• Wheel specification: no more than 9" wide with 5"-5.5" of backspacing recommended for proper 37" tire clearance

Features

• Full-length progressive rate leaf spring designed and built by Deaver Spring Inc. specifically to Carli Suspension specifications
• 9-leaf main pack with 3-leaf overload provides far more spring rate progression than the factory 2-4 heavy main springs with immobile overload
• Progressive design softens initial rate at ride height for dramatically improved daily driving comfort, then increases rate under load
• 3" rear lift provides balanced stance when paired with Carli 4.5" and 5.5" front lift suspension systems
• Supports up to 15" of rear wheel travel for significantly increased articulation over stock
• Relocated center pin accommodates up to 38" tires (37" recommended) without rear fender well contact at full compression
• Block-eliminating design removes factory lift blocks for improved ride quality and reduced axle wrap
• Minimizes axle wrap and wheel hop for improved traction during acceleration, towing, and off-road driving
• "Light" 3/4-ton cargo capacity - full factory payload capacity attainable with Carli Long Travel Airbags

Specifications

• Part Number: AP-FFSP-17
• Brand: Carli Suspension
• Manufacturer: Deaver Spring Inc. (built to Carli specifications)
• Type: Full Progressive Rear Leaf Spring
• Rear Lift Height: 3 in.
• Spring Design: 9-Leaf Main Pack + 3-Leaf Overload, Progressive Rate
• Maximum Wheel Travel: 15 in.
• Axle Tube Compatibility: 3.5"-4.0" diameter
• Recommended Tire Size: Up to 37 in. (38 in. maximum)
• Quantity: Sold Individually
• Compatible Carli Systems: CS-FFSP-17 (4.5"/5.5" lift leaf spring kit)
• Position: Rear

Included Components

• 1x Carli AP-FFSP-17 Full Progressive Rear Leaf Spring (sold individually - U-bolts, bump stop drops, and hardware sold separately or included in kit SKU CS-FFSP-17)

Product Description

The Carli AP-FFSP-17 is a full-length progressive rear leaf spring providing 3 inches of rear lift, designed specifically for the 2017-2025 Ford F-250 and F-350 Super Duty 4WD diesel trucks. Built by Deaver Spring Inc. to Carli Suspension's precise specifications, this spring replaces the harsh factory leaf spring pack - which typically uses just 2 to 4 heavy main springs with an immobile lower overload - with a far more refined 9-leaf main pack and 3-leaf overload configuration. This progressive multi-leaf design delivers dramatically improved ride quality at normal ride height while progressively increasing resistance as the suspension compresses under load, engaging additional leaves for impressive cargo capacity when needed.

The 3" rear lift is engineered to provide a 1" rear-high stance when paired with Carli's 4.5" and 5.5" front lift suspension systems, giving the truck a purposeful, slightly rear-biased profile that accommodates heavy towing and hauling. With up to 15 inches of available wheel travel, these springs deliver significantly more articulation than stock, making them ideal for both highway comfort and serious off-road capability. The relocated center pin position allows full compression travel with up to 38" tires (37" recommended) without the tire contacting the front of the rear fender well - a critical improvement over factory spring geometry when running larger tires.

This spring is sold individually and is a component of the complete CS-FFSP-17 leaf spring kit, which includes both springs, U-bolts, rear bump stop drops, and all necessary hardware. It is important to note that Carli full replacement leaf springs are designed to work in conjunction with Carli custom-valved shocks - they will not perform optimally with off-the-shelf shock valving from other manufacturers. The "light" 3/4-ton cargo capacity is the trade-off for the significantly improved unloaded ride quality; however, full factory payload capacity can be restored by adding Carli Long Travel Airbags. For trucks running Carli 2.5" leveling systems, the AP-FFSP-LVL-08 spring provides the appropriate 1" rear lift instead.