Cognito 12" Performance Lift Kit with Fox 2.0 PSRR | 2020-2025 Silverado/Sierra 2500HD/3500HD

The Obsidian Vision

Twelve inches of front lift and nine inches of rear lift on a 2020–2025 Silverado or Sierra 2500HD/3500HD is the outer boundary of what a properly engineered T1 GMT1XX heavy-duty platform can achieve — and it begins with a non-negotiable requirement: the stock front driveline is not supported with this kit on 4WD trucks, and a CV front driveline upgrade must be in place before the vehicle is operated in 4WD under any conditions. With that foundation established, the Cognito 12-Inch Performance Lift Kit with Fox 2.0 Performance Series Remote Reservoir Shocks delivers the transformation as a complete, no-guesswork system: SM Series Ball Joint Upper Control Arms, SM Series Compression Struts, the patented Pitman and Idler Arm Support Kit, Fox 2.0 PSRR front shocks, forged torsion bar keys, Deaver replacement leaf packs, a 5-inch block and U-bolt kit, and stainless steel braided brake lines — every component engineered, manufactured, and assembled in the USA, and sized to clear a 40x13.5-inch tire on a 10-inch wide wheel. At $8,673.77, this is the Fox 2.0 PSRR entry point into the Cognito 12-inch T1 lift system — the same platform, the same lift, the same CV driveline requirement as the Elka Elite package, with Fox's proven remote reservoir damping technology at a lower price point.

Concierge Fitment Guarantee

Every order is manually reviewed by our technicians to ensure 100% compatibility with your build before we ship.

Engineering Breakdown

• Lifts the front of the 2020–2025 Silverado/Sierra 2500HD/3500HD 12 inches via the Cognito SM Series Ball Joint Upper Control Arm Kit, SM Series Compression Struts, and forged torsion bar keys working in concert to correct ball joint and CV joint angles at extreme lift height — maintaining adequate front droop travel, corrected CV joint geometry, and long-term front suspension component integrity across the full 12-inch lift range on the T1 platform's front suspension architecture.
• Eliminates the pitman and idler arm center-link movement that causes steering play, road wander, and accelerated steering component wear at extreme lift heights through the patented Cognito Pitman and Idler Arm Support Kit — the engineering solution to the inherent wear problem that has plagued GM truck steering systems for decades and is amplified at 12 inches of front lift on the T1 platform.
• Levels the truck front to rear with 9 inches of rear lift via Deaver replacement leaf packs (4 inches over stock) combined with the Cognito 5-inch block and U-bolt kit, with the Fox 2.0 Performance Series Remote Reservoir shocks delivering factory-tuned precision valving and remote reservoir oil volume management that eliminates aeration and maintains consistent damping performance across the full 12-inch front lift travel range.

The Cognito SM Series Ball Joint Upper Control Arms feature boxed sheet-metal construction, welded seams, and semi-gloss black powder coat, with pre-installed maintenance-free ball joints and pivot bushings. The SM Series Compression Struts are required at 12 inches of front lift to maintain correct CV joint operating angles that the upper control arm alone cannot fully address at this lift height on the T1 platform. The forged torsion bar keys are the front ride height adjustment component specific to the T1 2500HD/3500HD torsion bar front suspension, providing the mechanical advantage required to achieve 12 inches of front lift without over-cranking factory adjuster keys beyond their designed range. The Fox 2.0 Performance Series Remote Reservoir shocks feature an impact-extruded aluminum body for increased cooling capacity, rust-resistant construction, and factory-tuned precision valving that eliminates oil aeration for consistent damping performance — delivering a comfortable on-road ride and predictable off-road handling in the toughest conditions at 12 inches of front lift. The Deaver leaf pack is a complete OEM spring replacement arched for 4 inches over stock rear lift height, manufactured from high-quality spring steel with a higher leaf count and thinner leaf material for a more compliant progressive rate. The Cognito 5-inch block and U-bolt kit adds the remaining 5 inches of rear lift, with powder-coated semi-gloss black steel blocks and heavy-duty zinc plated U-bolts completing the 9-inch total rear lift system. Stainless steel braided brake lines are included to safely accommodate the increased suspension travel at 12 inches of front lift. All Cognito components are engineered, manufactured, and assembled in the USA. At 708 lbs, this kit ships via LTL freight carrier on multiple pallets with residential delivery included.

Audit Table

Verified Fitment (OFAS Standard)

✅ CONFIRMED — Chevrolet Silverado 2500HD:
2020–2025 Chevrolet Silverado 2500HD Base, Custom, WT, LT, LTZ, High Country 2WD/4WD

✅ CONFIRMED — Chevrolet Silverado 3500HD:
2020–2025 Chevrolet Silverado 3500HD Base, WT, LT, LTZ, High Country 2WD/4WD SRW & DRW

✅ CONFIRMED — GMC Sierra 2500HD:
2020–2022 GMC Sierra 2500HD Base 2WD/4WD
2020–2025 GMC Sierra 2500HD SLE, SLT, AT4, Denali 2WD/4WD
2023–2025 GMC Sierra 2500HD Pro 2WD/4WD
2024–2025 GMC Sierra 2500HD Denali Ultimate 2WD/4WD

✅ CONFIRMED — GMC Sierra 3500HD:
2020–2022 GMC Sierra 3500HD Base 2WD/4WD
2020–2025 GMC Sierra 3500HD SLE, SLT, AT4, Denali 2WD/4WD SRW & DRW
2023–2025 GMC Sierra 3500HD Pro 2WD/4WD SRW & DRW
2024–2025 GMC Sierra 3500HD Denali Ultimate 2WD/4WD SRW & DRW

❌ REQUIREMENTS & CRITICAL NOTICES:
⚠️ CV FRONT DRIVELINE REQUIRED — 4WD TRUCKS: The stock front driveline is NOT supported with this kit on 4WD trucks. A CV front driveline upgrade must be installed before operating the vehicle in 4WD under any conditions. Failure to install a CV front driveline before engaging 4WD will result in driveline damage. Contact the OFAS team to confirm the correct CV driveline for your specific truck before ordering.
Requires front alignment immediately post-installation — at 12 inches of front lift, caster and camber correction is critical before any driving. Do not operate the vehicle before alignment is completed.
Requires driveline u-joint angle verification post-installation — at 12 inches of front lift and 9 inches of rear lift, driveline operating angles must be verified and corrected before towing at rated capacity.
Requires ADAS recalibration if equipped with forward collision alert, lane departure warning, adaptive cruise control, or Super Cruise.
Requires professional brake system inspection post-installation to verify stainless braided brake line routing, clearance, and connection integrity before driving.
Requires rear U-bolt re-torque after the first 500 miles of use.
Shipping Notice: At 708 lbs, this kit ships via LTL freight carrier on multiple pallets. Residential delivery is included.

Installation & Technical Notes

Estimated Install Time: 18-Hour DIY Install — this is a complete front and rear suspension system replacement requiring a 2-post or 4-post lift, comprehensive hand tools, torque wrench, spring compressor, torsion bar unloading tool, and alignment equipment or an immediate post-installation alignment appointment.
CV Driveline: Install the CV front driveline upgrade before engaging 4WD under any circumstances. The stock front driveline is not supported with this kit — this is a hard requirement for all 4WD operation, not a speed-limited advisory.
Torsion Bar Keys: Unload the factory torsion bars completely before removing the factory adjuster keys. Install the forged Cognito keys and set ride height per Cognito's included instructions — verify droop travel is adequate after setting height before finalizing.
Alignment Required: Yes — professional front alignment is mandatory immediately after installation. At 12 inches of front lift, caster and camber deviation from factory specification is at its maximum and must be corrected before any driving.
Torque Specifications: Refer to Cognito's included instruction sheet for all component torque values — torque all fasteners with the suspension at ride height under load. Re-torque all critical fasteners after the first 500 miles.
Brake Line Routing: Route and secure stainless braided brake lines per Cognito's included instructions — verify clearance to all suspension components through the full travel arc before driving.
Shock Comparison: If adjustable high- and low-speed compression damping tuning is a priority for your build, consider the Elka 2.5 Reservoir package (210-P1178) — the Fox 2.0 PSRR delivers excellent factory-tuned performance without user-adjustable compression damping.
Shipping Notice: At 708 lbs on multiple pallets, coordinate delivery logistics before ordering. Residential delivery is included but requires a clear delivery path and personnel to assist with unloading.

Wheel & Tire Fitment

Maximum Confirmed Tire Size: 40x13.5" on a 10-inch wide wheel with 4.5-inch backspacing — verified clearance with this kit at 12 inches of front lift and 9 inches of rear lift on the 2020–2025 Silverado/Sierra 2500HD/3500HD platform.
Wheel Width: 10 inches recommended for maximum tire size
Maximum Backspacing: 4.5 inches with 40x13.5" tires
Contact the OFAS team to verify inner fender clearance, fender flare compatibility, and offset requirements for your specific cab, bed, and fender configuration before finalizing wheel and tire selection at this tire size.

Our team is standing by to confirm your CV front driveline selection, torsion bar spring rate, drivetrain configuration, and 40-inch tire and wheel setup for your specific truck. Purchase with confidence; we review every build.