2007–2018 Chevy/GMC Silverado & Sierra 6-Inch Rear Lowering Kit (For Cast Aluminum Spindles)

True 6" Rear Drop • Flip Kit + Inverted Shackle • Uses Factory GM Shackle • Perfect Geometry • Smooth Ride • Heavy-Duty Design

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Lowering the rear of a 2007–2018 Chevy Silverado or GMC Sierra 1500 dramatically changes the stance, style, and road presence of the truck. These GMT900 and K2XX platform trucks are known for their durability, smooth ride, and responsive handling—and lowering them the right way requires parts engineered specifically for their frame, leaf spring design, and rear axle configuration.

This 6-Inch Rear Lowering Kit is designed for trucks equipped with cast aluminum spindles and is built for owners wanting a more extreme, sleek, and aggressive drop while maintaining safe suspension geometry, full drivability, and consistent load capability. Unlike block kits or unsafe DIY methods, this system relocates the axle above the leaf springs (a classic “flip kit”) and re-engineers the rear shackle mounting bracket to invert the orientation, allowing you to use your factory GM shackle for the final drop.

The result is a true, stable, geometry-correct 6" drop that looks incredible, performs well, and works perfectly with 20”, 22”, and even 24” wheel setups. This is the professional-grade lowering solution your Silverado or Sierra deserves.

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COMPATIBLE VEHICLES

This kit is engineered for:

2007–2018 Chevy Silverado 1500 

2007–2018 GMC Sierra 1500 

All 2015 (and some 2014 4×4 and early 2016) Silverado/Sierra’s come with one of two spindle types. You need to check which kind you have to ensure you get the correct products.

Important:
GM used cast aluminum and stamped steel spindles in certain years. This kit is designed specifically for trucks with cast aluminum spindles.

If you are unsure of your spindle type, please see image for clarification. 

Does NOT fit:

• 2500HD or 3500HD

• 2019+ newer body style

• Trucks with aftermarket coil spring conversions

• Air-ride equipped trucks (unless modified)

• Stamped steel spindle trucks

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WHY THIS KIT USES A FLIP SYSTEM + INVERTED SHACKLE

This 6-inch drop system is based on a proven lowering architecture that provides:

1. Maximum Drop With Maintained Geometry

By moving the axle from under the leaf springs to on top, you instantly gain a large, stable amount of lowering without changing the spring rate or load capacity.

2. Inverted Shackle Mounting Bracket

Instead of using a long aftermarket shackle, this system flips the mounting orientation so you can use your OEM GM shackle.

This is important because:

• OEM shackles are stronger

• OEM shackles have proper articulation

• No oversized shackle = better geometry

• OEM shackle bushings last longer

• You avoid the “spring bind” issue caused by long shackles

3. No Lowering Blocks

Blocks cause:

• Axle wrap

• Wheel hop

• Harsh ride

• Driveshaft vibration

• Reduced towing capacity

• Rear-end instability

This 6-inch lowering system avoids all those issues by lowering correctly through design—not force.

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WHAT MAKES THIS 6-INCH DROP DIFFERENT FROM THE 4" OR 5" VERSIONS

You mentioned it perfectly:
This kit works just like the 4-inch and 5-inch cousins—using a flip kit and shackle mount changes—but the difference lies in the final drop height method.

Differences from 4-inch Kit

4” = flip kit + standard shackle mount
You keep more ride height and rake.

Differences from 5-inch Kit

5” = flip kit + longer aftermarket shackle
This adds an extra 1 inch of lowering.

How the 6-inch Kit Works

6” = flip kit + inverted shackle mount while using your OEM shackle

This method:

• Lowers the truck a full extra inch beyond the 5” system

• Preserves OEM strength and articulation

• Avoids the “extra-long shackle sway” issue

• Provides cleaner suspension geometry

• Maximizes stance without introducing block-style issues

This is the safest and cleanest way to get a true 6-inch drop.

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BENEFITS OF A 6-INCH REAR DROP

1. More Aggressive, Show-Ready Stance

A 6-inch rear drop gives a show-truck profile and pairs well with:

• 3-inch front drop

• 4-inch front drop

• Drop spindles + lowering coils

• Torsion bar drop arms (on 4x4 lowered builds)

You can achieve:

• A 3/6 drop

• A 4/6 drop

• A 5/7 static stance (if combined with alternative front components)

2. Improved Handling & Cornering

Lowering the rear reduces:

• Body roll

• Weight transfer

• Rear-end sway

• Highway wandering

The truck feels more planted, confident, and stable.

3. Perfect Wheel Fitment

This drop looks incredible with:

• 20x10

• 22x10.5

• 24x10

• 24x12 (with trimming/offset)

Wheel gap disappears without causing excessive rubbing (wheel/tire dependent).

4. Excellent for Static Drop Builds

A 6-inch rear drop is ideal for:

• Daily-driven lowered trucks

• Slammed street builds

• Show trucks

• Audio builds

• Wide wheel setups

• Tucked or flush tire fitment

5. Maintains OEM Spring Rate

Your ride doesn’t become harsh or bouncy.

6. Preserves Load Capability

You can still:

• Haul

• Tow (within reason)

• Carry cargo

…without the instability caused by lowering blocks.

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RIDE QUALITY: SMOOTH, CONTROLLED, STABLE

This lowering kit maintains:

• Full leaf spring arc

• Correct pinion angle

• Proper driveshaft alignment

• Safe suspension articulation

• Factory-like ride quality

Because GM leaf springs remain in their designed arc (just relocated), the ride stays exceptionally smooth.

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SHOCKS ARE NOT INCLUDED — BUT ARE REQUIRED

DJM recommends:

Rear Shock: DJM 1900

Tuned specifically for:

• Lowered ride height

• Reduced rebound bounce

• Proper compression travel

• Improved stability

Using factory shocks will cause:

• Bouncing

• Bottoming out

• Poor handling

• Dangerous instability on highway dips

Upgrading to DJM 1900 is strongly recommended.

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INSTALLATION OVERVIEW

Time Required:

4–7 hours (depending on tools and rust)

Skill Level:

Intermediate

Tools Needed:

• Jack + jack stands

• Impact gun

• Ratchet/socket set

• Torque wrench

• Grinder or air hammer (for rivet removal if needed)

• Pry bars

• Safety glasses

Rear Flip Procedure:

1. Remove U-bolts

2. Lower rear axle

3. Relocate axle above leaf spring

4. Install flip brackets

5. Reverse shackle mount orientation

6. Install OEM GM shackles into new mount

7. Verify clearance

8. Install new shocks

9. Torque everything to spec

A professional alignment is recommended if the front is lowered as well.

Rear-only lowering does not require alignment.

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PERFECT FOR STREET TRUCK ENTHUSIASTS

This kit is ideal for:

• Slammed street builds

• Tucked-wheel setups

• Static drop trucks

• Show trucks

• Daily driven customs

• Wide wheel offsets

• Modified exhaust systems

• LED tailgate strip trucks

• Audio competition trucks

…a 6-inch rear drop is the foundation.

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WHY BUY FROM GAUGE STORE?

With decades of experience in:

• Suspension

• Custom trucks

• Slamology

• Gauge Magazine feature builds

• Static-drop performance

• Real-world testing

Gauge Store offers:

✔ Expert suspension knowledge
✔ Guaranteed fitment
✔ Fast shipping
✔ Trusted brands only
✔ Premium customer support
✔ Real-world installation advice

We don’t just sell lowering parts — we build with them.