ReadyLIFT 2.5-Inch Forged Torsion Key Leveling Kit | Shock Extensions + Custom Adjusting Bolts | 2000–2010 Silverado/Sierra 1500 / 2500HD 8-Lug; 2000–2012 Suburban/Yukon XL 2500 HD 8-Lug; 2005–2010 Hummer H2 | SKU: 66-3050

Verified Fitment

Does NOT fit:

• 6-lug GM 1500 trucks (1999–2006 GMT800 platform) — this kit is for 8-lug trucks only; 6-lug Silverado/Sierra 1500 owners should see ReadyLIFT's separate 6-lug 1500 leveling kit
• 2011 and newer GM HD — different torsion bar suspension design; order ReadyLIFT 66-3011 (2011–2019) or 66-30200 (2020–2026)
• 2004 and earlier Hummer H2 — H2 fitment confirmed from 2005 only
• 2011 and newer Hummer H2 — production ended 2009; no 2011+ H2 exists
• Hummer H3 — different suspension platform
• Cadillac Escalade 2WD/4WD — see ReadyLIFT's separate Escalade/Tahoe/Suburban 6-lug kit

8-lug identification: The 2000–2010 GM 1500 was available in both 6-lug (standard) and 8-lug (heavy-duty package / 2500-based) configurations. Confirm your wheel bolt pattern before ordering. Count the lug nuts on your front wheel — 8 lugs = this kit applies; 6 lugs = different kit required.

2008–2010 HD truck installation variant: Trucks from model years 2008–2010 HD will need to use the factory torsion key adjusting bolt to achieve the desired 2.5 inches of lift. The included custom adjusting bolts in this kit are optimized for 2000–2007 trucks. 2008–2010 HD owners will use the factory adjusting bolt rather than the included custom bolt — see installation notes.

Component Specifications

Flat-grip torsion bar design: The 2000–2010 GM HD torsion bar has a flat surface on its key engagement area. ReadyLIFT's torsion keys are specifically designed to contact and grip this flat — unlike rounded-contact keys that can rock slightly on the bar's surface under load. The flat-grip design produces a tighter, more stable engagement with the torsion bar, which reduces the potential for key movement or rotation during suspension cycling.

CNC-machined adjuster bolt pockets + 10.9 grade hardware: The adjuster bolt pocket is the critical point where the torsion bar preload is set. CNC machining ensures this pocket is dimensionally precise — the bolt seats correctly, the preload is set accurately, and the pocket does not deform under the clamping load. The 10.9 grade metric hardware (equivalent to SAE Grade 8) prevents stripping during preload adjustment.

Custom adjusting bolts — over-crank prevention: The included custom-length adjusting bolts function as a physical limit on how much preload can be set. This prevents the installer from accidentally over-cranking the torsion bar, which on the 2000–2007 trucks can eliminate down travel and produce the same top-off condition described in the newer-platform kits. The 2008–2010 HD trucks do not use these custom bolts — the factory adjusting bolt is used on those model years.

Field 4 — What Is and Is NOT Included

2008–2010 HD trucks — note on included custom bolts: The included custom adjusting bolts are designed for 2000–2007 model year trucks. Owners of 2008–2010 HD trucks will use the factory torsion key adjusting bolt rather than the included custom bolt to achieve the desired 2.5 inches of lift. Do not force the custom bolt into a 2008–2010 truck application — use the factory bolt.

Critical Compatibility

8-lug is the primary gate. This kit covers both the 1500 and 2500HD designations on the 2000–2010 platform, but only 8-lug configurations. The standard 6-lug 1500 Silverado/Sierra uses a different torsion bar setup covered by a separate ReadyLIFT kit. If your truck has 6 lug nuts on each front wheel, this kit does not apply.

2011+ GM HD are completely different platforms. The 2011 GM HD suspension redesign was significant — the 66-3050 keys are not compatible with 2011 or newer HD trucks. Order 66-3011 for 2011–2019 or 66-30200 for 2020–2026.

Hummer H2 fitment range is 2005–2010 only. The H2 fitment has been confirmed from 2005 forward. Pre-2005 H2 (2003–2004) is not in ReadyLIFT's confirmed fitment data for this kit.

2008–2010 HD adjusting bolt variant is an installation detail, not a compatibility issue. All 2000–2010 HD 8-lug trucks fit this kit. The difference for 2008–2010 is only which adjusting bolt to use during installation — the factory bolt replaces the custom included bolt for those model years.

Installation Notes

Skill level: Intermediate — torsion key swap. Requires torsion bar unloading tool. Professional installation recommended.

Mandatory tool — torsion key unloading tool (not included): Required before removing factory torsion keys. Not included in the 66-3050. Source a ReadyLIFT-compatible torsion key unloading tool before scheduling installation.

2008–2010 HD truck adjustment note: Do not use the included custom adjusting bolts on 2008–2010 model year HD trucks. Use the factory torsion key adjusting bolt on these trucks to set the desired lift. The included custom bolts are for 2000–2007 trucks only.

Installation sequence:

1. Safely lift and support vehicle with front suspension at full droop.
2. Use torsion key unloading tool to fully relieve torsion bar preload.
3. Remove factory torsion keys.
4. Install ReadyLIFT 66-3050 forged torsion keys — confirm flat engagement with the torsion bar's flat contact surface per installation instructions.
5. Install shock extension spacers at front shock mounting locations.
6. 2000–2007 trucks: Use included custom adjusting bolts to set torsion key preload to desired lift height — custom bolt length prevents over-cranking.
7. 2008–2010 HD trucks: Use factory torsion key adjusting bolt to set preload to desired lift height.
8. Lower vehicle, confirm equal ride height on both sides, and verify no top-off condition (truck should have visible suspension down travel available).

Post-installation mandatory steps:

1. Professional 4-wheel alignment — mandatory.
2. Headlamp aim adjustment — required.
3. ADAS verification — check all applicable systems.
4. Test fit tires — especially important on the Hummer H2 at 37" fitment; verify full articulation and steering lock clearance before mounting.

Common Questions

How do I know if my 2000–2010 Silverado is 8-lug?
Count the lug nuts on any wheel. 8 lug nuts = 8-lug configuration — this kit fits. 6 lug nuts = 6-lug configuration — this kit does not fit; see ReadyLIFT's separate 6-lug kit.

What's the difference between the 66-3050 and the 66-3011?
Platform generation and suspension size. The 2000–2010 GM HD torsion suspension is one generation; the 2011 HD introduced an entirely new, larger suspension design that is dimensionally incompatible with 2000–2010 keys. The 66-3050 is engineered for the older platform; the 66-3011 is engineered for the 2011–2019 platform. These kits are not interchangeable between generations.

My truck is a 2009 Silverado 2500HD — which adjusting bolt do I use?
Use the factory torsion key adjusting bolt. The included custom adjusting bolts in the 66-3050 are designed for 2000–2007 trucks. For 2008–2010 HD trucks, the factory bolt is used to achieve the 2.5-inch lift.

What does "grabs the FLAT of the torsion bar" mean?
The torsion bar on this platform has a flat surface at the key engagement area. ReadyLIFT's torsion keys are specifically machined to contact and grip this flat — rather than making rounded contact with the bar surface. Flat-to-flat contact produces a tighter, more stable engagement that resists key movement or rotation under suspension load.

Does this fit my Hummer H2?
Yes — for 2005–2010 H2 models. The H2 has a larger tire clearance benefit from this kit: 37" x 12.50 on a 9" wheel at +12 offset clears without rubbing, compared to 33" maximum on the GM truck applications.

Do I need to source a torsion key unloading tool?
Yes — it is required and not included. Source a ReadyLIFT-compatible torsion key unloading tool before scheduling installation.

The Obsidian Take

The 66-3050 is the foundational ReadyLIFT torsion key kit for the 2000–2010 8-lug GM HD platform — the leveling solution that covers everything from the GMT800-era 2500HD through the 2012 Suburban/Yukon XL 2500 HD and the H2. The core engineering that makes it the industry standard is the same across every ReadyLIFT torsion key product: forged steel at 25% stronger than OEM, flat-grip contact with the torsion bar's flat surface, CNC-machined adjuster bolt pockets, and 10.9 grade hardware.

The custom adjusting bolt is the feature that separates this kit from competitors on 2000–2007 trucks. Most alternative kits leave the installer free to over-crank the torsion bar — which eliminates down travel, produces a harsh ride, and wears components prematurely. The included custom-length adjusting bolt acts as a physical limit that prevents that error during installation. For 2008–2010 HD trucks, the factory bolt is used instead — ReadyLIFT accounts for the platform variation explicitly.

The Hummer H2 application is worth calling out separately. The H2 sits on a larger platform with more wheel well space than the Silverado/Sierra — at this same 2.5-inch lift, the H2 clears 37" x 12.50 on a 9" wheel at +12 offset without rubbing. That's a meaningfully larger tire than the 33" maximum on the truck applications. H2 owners leveraging this kit get a legitimate large-tire platform upgrade, not just a level stance.

This SKU is for: 2000–2010 Chevy Silverado and GMC Sierra 1500/2500HD 8-lug owners, 2000–2012 Suburban/Yukon XL 2500 HD 8-lug owners, and 2005–2010 Hummer H2 owners who want a 2.5-inch forged torsion key leveling solution with shock extensions, custom over-crank-prevention adjusting bolts, and a Lifetime Warranty — and who have sourced a torsion key unloading tool before installation.

This SKU is NOT for: 6-lug 1500 Silverado/Sierra owners (different kit required), 2011 and newer GM HD owners (order 66-3011 or 66-30200), 2003–2004 Hummer H2 owners (not confirmed in fitment data), or anyone who has not sourced the torsion key unloading tool before installation.

SAE J2492 Warning
⚠ WARNING: By installing this product, you acknowledge that the suspension of this vehicle has been modified. As a result, this vehicle may handle differently than factory-equipped vehicles. As with any vehicle, extreme care must be used to prevent loss of control or rollover during sharp turns or abrupt maneuvers. Always wear seat belts, and drive safely, recognizing that reduced speeds and specialized driving techniques may be required. Failure to drive this vehicle safely may result in serious injury or death. Do not drive this vehicle unless you are familiar with its unique handling characteristics and are confident of your ability to maintain control under all driving conditions.

Manufacturer Data Disclaimer
Product specifications, fitment data, and feature details are sourced from ReadyLIFT manufacturer documentation and verified third-party technical references current at the time of publication. ReadyLIFT reserves the right to modify product specifications without notice. Confirm 8-lug configuration, 2000–2010 platform, and 2008–2010 HD adjusting bolt variant before ordering. OFAS is not responsible for incompatibility resulting from 6-lug applications, 2011+ platform applications, unconfirmed pre-2005 H2 applications, or incorrect adjusting bolt use on 2008–2010 HD trucks.

Prop 65 Warning
⚠ WARNING: This product can expose you to chemicals including lead and lead compounds, which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information, go to www.p65warnings.ca.gov.

Non-Returnable Notice
This item is non-returnable once installed. Verify 8-lug configuration, model year, and platform generation before ordering. Questions before ordering? Text (469) 407-7538.