Carli Linear-Rate coil springs are built with a custom wind, giving them a smooth linear rate and improved ride over stock. Their design delivers subtle initial compression feel on highway chatter and small bumps as well as smooth compression deeper into the travel. Of course travel is another key point. Unlike most level coils that are about height, these level the truck and increase wheel travel to a massive 9.5" up front. 
All 17+ trucks all use the same Carli coil part numbers for the Diesel variant, and the same part number for the gas variant. 17-20 F-250/350 trucks are a 2.5” height increase from factory with a level coil and Tremors are typically 1.5". Normal 20+ Super Duty trucks typically get 3.5” of height increase since Ford actually lowered those trucks from 2020 forward. That said, certain trim packages will sit trucks higher (ie snow plow prep etc) which will influence the lift height relative to stock height. 

That said, the final hood and roof height is identical between trucks regardless of the year and trim package since the change in measured lift height is just due to the difference in starting factory coil height. Once those come off and the Carli coils go in, the difference is gone. In short, we like to refer to these as "level height" coils, as referring to specific lift is tricky thanks to how much variance Ford has from the factory depending on trim and options. 
SKU: CS-FLC-05
– Fitment: 2020-23 F250/350 4×4, Diesel – 3.5″ of lift
– Fitment: 2005-19 F250/350 4×4, Diesel – 2.5″ of lift
– Linear Rate Spring
– Shot peened & Pre-set for Maximum Durability
– Powder Coated for finish longevitySKU: CS-FLC-11-GAS 
- Fitment: 2020+ F250/350 4x4, GAS - 3.0" of lift
- Fitment: 2011-19 F250/350 4x4, GAS - 2.5" of lift
- Linear Rate Spring
- Shot peened & Pre-set for Maximum Durability
- Powder Coated for finish longevity