6-Inch Lift Kit with M1 Shocks for 2017-2022 Ford Super Duty 4WD — Part 55440
- Fits 2017-2022 Ford F-250 and F-350 Super Duty 4WD in King Ranch, Lariat, Limited, Platinum, XL, and XLT trims
- Excluded: gas engines, dually axles, manual shift transfer cases, 3.5 in rear axle tubes, and Tremor package trucks
- Requires factory contact overload springs at the rear axle
- Two M1 monotube shock pairs, radius arm drop brackets, 6 inch coils, and a 6.5 in fabricated rear block package
- Bolt-on install with a downloadable installation guide available
The Trail Fortress check
Will it fit your truck?
✓ Fits
✕ Does not fit
- Gas engine models
- Dually models
- Manual shift transfer cases Does NOT fit models with 3.5" rear axle tube ONLY fits models equipped with rear factory contact overload springs Does NOT work on models equipped with Tremor Factory Trim Package
About this kit
6-Inch Lift Kit with M1 Shocks, fitment-checked
Rough Country 55440 is a 6-inch lift kit for 2017-2022 Ford F-250 and F-350 Super Duty 4WD models, built around radius arm drop brackets, front coils, fabricated rear blocks, a transfer case clocking kit, and two pairs of M1 monotube shocks. Diesel-only fitment: it does not fit gas engines, dually models, manual shift transfer cases, a 3.5 in rear axle tube, or the Tremor trim package.
This 6-inch lift kit for the 2017-2022 Ford Super Duty 4WD covers F-250 and F-350 trims from XL through Limited, and bolts on with radius arm drop brackets that keep caster set where the factory geometry expects it. The box carries a 6 inch coil set, radius arm upgrade boxes, a 6.5 in rear block and U-bolt kit, universal U-bolts, a transfer case clocking kit, and two M1 monotube shock pairs. Your truck must have factory contact overload springs at the rear. Read the exclusion list closely, then work from the downloadable Rough Country installation guide.
What’s in the box
Kit contents
- 1× 6.5 In Block U-Bolt Kitoverloads 1550BOX2
- 1× Radius Arm Kit Box 512BOX1
- 1× Transfer Case Clocking Kit 55003
- 1× M1 MONOTUBE SHOCK PAIR 770754P
- 1× M1 MONOTUBE SHOCK PAIR 770805P
- 1× Univ. 3 4 X 4 1 X 1 2in U-Bolt Kit 7675
- 1× 6 Inch Coil Box 9296
- 1× Radius Arm Upgrade Box 53600991A
- 1× Radius Arm Upgrade Box 53600992A
Rough Country shares subassemblies across kits, so individual package labels can carry broader application ranges. The complete 55440 kit fits the vehicles shown in the fitment section above.
Specifications
Specs
| Brand | Rough Country |
| Part number | 55440 |
| UPC / GTIN | 00840269917943 |
| Lift height | 6 in |
| Shock package | M1 series |
| Shipping weight | 304 lb |
| Country of origin | US |
| Category | Suspension & Lift Kits › Lift Kits |
| Installation guide | Downloadable PDF |
Why buy here