CST 10" STL Stage 3 Suspension System — 20+ Chevy / GMC HD 2500HD/3500HD 4WD

A true 10" of lift on a one-piece subframe — built for the diesel/Allison HD — for 2020–2025 Chevy Silverado / GMC Sierra 2500HD & 3500HD 4WD (Duramax/Allison). The flagship CST system: maximum height and clearance with extreme-duty steering and a CV front driveshaft.

What this stage includes

• One-piece welded subframe with laser-cut fabricated spindles
• CST boxed upper control arms
• One-piece differential-drop crossmember with sway-bar extensions
• Extended-length CST Extreme-Duty tie rods
• CV-style front driveshaft (diesel/Allison)
• Soft-ride rear leaf springs, 2" lift blocks, 1–2 torsion keys, and an HD rear U-bolt kit
• Plus CST PRO-Series 2.5 reservoir front and piggyback rear shocks, with compression adjusters

Why CST

• A true 10" of lift with no cutting or modifying the factory torsion X-member or UCA pocket
• One-piece subframe for maximum ground clearance and front-end protection
• Extreme-duty tie rods and a CV driveshaft built for the weight of the diesel/Allison
• Precision-fabricated in-house by CST in the USA

Good to know

• Built specifically for 2020+ Duramax diesel / Allison 4WD trucks
• Soft-ride rear leaf springs are not designed for towing — add air bags for load
• Clears 38" tires with no trimming, or 40s with minor trimming (20x9, 4.79" backspacing)
• Professional installation and alignment recommended