Cognito Super Stock Kit | 2024+ 2500HD AT4X/ZR2

Cognito “Super Stock Kit” – 2024+ AT4X / ZR2 2500HD

Overview

Cognito calls this package the Super Stock Kit — designed specifically for the 2024+ GMC Sierra 2500HD AT4X and Chevrolet Silverado 2500HD ZR2.
Since these models can’t accept a traditional leveling kit, this package focuses on improving ride quality, steering durability, and suspension performance, while maintaining the factory geometry.

Factory Suspension Setup

The AT4X and ZR2 come factory-leveled via torsion bar and torsion key clocking — essentially matching the front height of a standard 2500HD running a 3” leveling kit.
However, the trucks still appear slightly nose-down because GM adds a 1.5” rear lift block from the factory.

Key factory design elements include:

• Unique upper and lower control arms designed for this model’s taller ride height
• Modified ball joint angle and slightly longer upper control arms
• Revised knuckles engineered for this specific geometry

While this setup works, GM’s configuration results in tie rod angles that no longer sit flat with the centerlink, leading to accelerated wear on the pitman and idler arms.

Cognito Steering & Suspension Improvements

This is where Cognito’s engineering makes the difference.
The patented Cognito Pitman and Idler Arm Support Kit (included in this package) eliminates the GM design flaw that causes premature wear to steering components and tires — greatly improving steering longevity and precision.

Increased Suspension Travel

From the factory, the AT4X/ZR2 has only 2" of front droop travel, which limits ride comfort over bumps, dips, and uneven terrain.

Cognito engineers developed a precise front shock spacer system for the OEM Multimatic DSSV shocks, increasing droop travel to just over 3” — a 50% improvement in usable travel.

The result: smoother, more compliant ride quality and reduced harshness from front shock top-out.

Cognito SM Series Upper Control Arms

To complete the package, Cognito includes their boxed sheet-metal SM Series Upper Control Arm Kit, designed exclusively for the AT4X/ZR2 platform.

While the factory arms are capable, upgrading to Cognito control arms shows you’re not willing to settle for stock — enhancing both performance and appearance.

Kit Features

Cognito SM Series Upper Control Arm Kit

• Added caster for improved alignment stability
• Maintenance-free pivot bushings
• Maintenance-free ball joints
• Powder-coated semi-gloss black finish

Cognito Pitman and Idler Arm Support Kit – patented steering support solution

Cognito DSSV Shock Extenders – increase front suspension droop to 3”

Approx. 3-hour DIY install time

Vehicle Fitment

2024–2025 GMC Sierra 2500HD AT4X

2024–2025 Chevrolet Silverado 2500HD ZR2

Warranty & Manufacturing

Limited Lifetime Warranty – applies to all Cognito-branded products.
Proudly Made in the USA – engineered and manufactured in Southern California.