4-Inch Diesel Lift Kit for Trail Boss & AT4 Silverado/Sierra 1500
- Diesel-specific front kit for 4 inches of lift
- Only fits Trail Boss and AT4 trucks with the 2-inch factory lift
- Covers 2025–2026 Silverado 1500 and Sierra 1500 in 4WD
- High-clearance crossmember, cast knuckles, and fabricated rear blocks in the box
- Cutting and drilling required — downloadable installation guide available
The Trail Fortress check
Will it fit your truck?
✓ Fits
✕ Does not fit
- Factory wheels
Requires cutting and drilling. ONLY fits Trailboss and AT4 models. 20-inch or larger aftermarket wheels are required. Wheels must feature 4.5in backspacing to fit. Please test fit wheels prior to installation. Some aftermarket wheels may require 0.25" wheel spacer #1065. Fitment on this page is based on the manufacturer’s application data.
About this kit
4-Inch Diesel Lift Kit, fitment-checked
The diesel build of the 4-inch Trail Boss and AT4 kit. Rough Country 110330D fits 2025–2026 Chevy Silverado 1500 LT Trail Boss and Custom Trail Boss and GMC Sierra 1500 AT4 in 4WD, combining a diesel-specific front kit with a high-clearance crossmember and cast driver and passenger knuckles. Cutting and drilling are required.
Two filters apply before you order: the truck needs the 2-inch factory lift that comes on Trail Boss and AT4 models, and the front hardware in this kit is the diesel version. Meeting both puts you in 2025–2026 Chevy Silverado 1500 LT Trail Boss or Custom Trail Boss, or GMC Sierra 1500 AT4, in 4WD. The kit brings a high-clearance crossmember, cast driver and passenger knuckles, and fabricated rear blocks that hold stock track width. Strut assemblies stay intact, cutting and drilling are required, and wheels need to be 20 inches or larger with 4.5 in backspacing.
What’s in the box
Kit contents
- 1× Universal Kit Box 110030991
- 1× 6in Kit Crossmember Box 217BOX11
- 1× Diesel 6in FR Kit Box 217BOX10
- 1× 6in FR Kit Box 21731994
- 1× 6in Kit Dr Knuckle Box 21730BOX5
- 1× 6in Kit Ps Knuckle Box 21730BOX6
Rough Country shares subassemblies across kits, so individual package labels can carry broader application ranges. The complete 110330D kit fits the vehicles shown in the fitment section above.
Specifications
Specs
| Brand | Rough Country |
| Part number | 110330D |
| UPC / GTIN | 00840269966620 |
| Lift height | 4 in |
| Shipping weight | 223 lb |
| Country of origin | US |
| Category | Suspension & Lift Kits › Lift Kits |
| Installation guide | Downloadable PDF |
Why buy here