Cognito 12" Elite Lift Kit with Elka 2.5 Reservoir Shocks | 2011-2019 Silverado/Sierra 2500HD/3500HD

The Obsidian Vision

Twelve inches of front lift and nine inches of rear lift on a 2011–2019 Silverado or Sierra 2500HD/3500HD is the outer boundary of what a properly engineered GMT900 heavy-duty platform can achieve — a complete suspension system transformation that demands precision at every component interface, from the forged torsion bar keys that set the front ride height increment to the Elka 2.5 Reservoir shocks that deliver high- and low-speed compression damping tuned to the specific demands of a 12-inch lifted heavy-duty build. The Cognito 12-Inch Elite Lift Kit delivers that transformation as a complete, no-guesswork system: SM Series Ball Joint Upper Control Arms, SM Series Compression Struts, the patented Pitman Idler Arm Support Kit, Elka 2.5 Reservoir front shocks, an HD front sway bar, 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 to work as a unified system at the most demanding lift height available for this platform. At $10,918, this is the build that leaves nothing on the table.

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 2011–2019 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.
• 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 Idler Arm Support Kit, and reduces body roll through the HD front sway bar — delivering the steering precision and vehicle control that a 12-inch lifted heavy-duty platform demands.
• 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 Elka 2.5 Reservoir shocks delivering precise high- and low-speed compression damping tuned for the specific weight, geometry, and terrain demands of a 12-inch lifted GMT900 heavy-duty build.

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. The forged torsion bar keys are the front ride height adjustment component specific to the GMT900 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 Elka 2.5 Reservoir shocks feature an external reservoir with increased oil volume for cooler operating temperatures, and precise high- and low-speed compression damping adjustment that allows the owner to tune the damping character to their specific load, terrain, and driving style without compromise. The HD front sway bar reduces body roll and improves traction at the elevated ride height. 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:
2011–2019 Chevrolet Silverado 2500HD WT, LT, LTZ 2WD/4WD
2015–2019 Chevrolet Silverado 2500HD High Country 2WD/4WD

✅ CONFIRMED — Chevrolet Silverado 3500HD:
2011–2019 Chevrolet Silverado 3500HD WT, LT, LTZ 2WD/4WD SRW & DRW
2015–2019 Chevrolet Silverado 3500HD High Country 2WD/4WD SRW & DRW

✅ CONFIRMED — GMC Sierra 2500HD:
2011–2014 GMC Sierra 2500HD WT 2WD/4WD
2011–2019 GMC Sierra 2500HD SLE, SLT, Denali 2WD/4WD
2015–2019 GMC Sierra 2500HD Base 2WD/4WD

✅ CONFIRMED — GMC Sierra 3500HD:
2011–2014 GMC Sierra 3500HD WT 2WD/4WD
2011–2019 GMC Sierra 3500HD SLE, SLT, Denali 2WD/4WD SRW & DRW
2015–2019 GMC Sierra 3500HD Base 2WD/4WD SRW & DRW

❌ REQUIREMENTS & CRITICAL NOTICES:
⚠️ CV FRONT DRIVELINE REQUIRED — 4WD TRUCKS: A CV front driveline upgrade is required for 4WD operation above 20mph. The stock front driveline cannot safely operate at the CV joint angles generated by 12 inches of front lift. Install the CV front driveline upgrade before engaging 4WD above 20mph — contact the OFAS team to confirm the correct CV driveline for your specific truck.
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, or adaptive cruise control.
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: 19-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 operating in 4WD above 20mph. The stock front driveline cannot safely sustain the CV joint angles generated by 12 inches of front lift at speed in 4WD.
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.
Elka DSC Setup: Set Elka high- and low-speed compression adjusters to the softest position initially and tune incrementally based on load, tire size, and terrain preference.
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.
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

At 12 inches of front lift and 9 inches of rear lift on the 2011–2019 Silverado/Sierra 2500HD/3500HD platform, tire sizing is determined by fender clearance, inner fender modification, and wheel backspacing. Contact the OFAS team for specific tire and wheel recommendations — at this lift height, 37-inch to 42-inch tires are common, and wheel backspacing, offset, and inner fender clearance must all be verified for your specific cab, bed, and fender configuration before finalizing wheel and tire selection.

Our team is standing by to confirm your CV front driveline selection, torsion bar spring rate, drivetrain configuration, and tire and wheel goals for a 12-inch build on your specific truck. Purchase with confidence; we review every build.