Lowering Blocks for Chevy Colorado Driveline Adjustment - V8 Swaps by JTR Stealth

Lowering Blocks for Chevy Colorado

  • $99.00

Why You Might Need One. Lowering blocks kits work with alignment shims that adjust driveline angles on swaps. Our lowering block kits include the required heavy-duty U-Bolts, Hi-Nuts, and extra aluminum lowering-block washers.

Why JTR Stealth? Like the lowering blocks we make for other vehicles, our rear suspension lowering kits for Chevy Colorado use lowering blocks made of solid (billet) aluminum.

The Stealth Conversions lowering blocks for the Colorado are unique in that the lower hole is 15/32" for 2004-2008 Colorados and 15mm for 2009 and newer trucks. You will be asked to designate the vehicle year when ordering.

The solid aluminum lowering blocks cost more than most other lowering blocks because of the high cost of solid aluminum, and the additional machining required to tap the hole. But they will not fail, and are more versatile than extruded or cast lowering blocks because they can be used with pinion alignment shims. In addition, the amount of lowering can be adjusted in 1/2" increments by bolting the 1/2" block to a 1", 2" or 3" lowering block.

Chevy Colorado lowering blocks, design to support half-inch increments, Stealth Conversions

If you only want to lower the rear 1/2", you can install the 1/2" lowering block directly to the leaf spring in the same manner that the pinion alignment shim is bolted to the leaf spring.  

Generally, lowering blocks taller than 3" (with 15" rims) are not recommended because this positions the lower spring bracket below the rim line (also called the "scrub line") and this is illegal in many states, because if the tire loses air, the bracket will drag on the ground, causing the vehicle to lose control.

Stock U-bolts vs. Stealth Conversions extra-long and strong U-bolts
U-bolts for Chevy Colorado lowering blocks, Stealth Conversions

The Stealth Conversion's U-bolts for the Colorado are made specifically for the Colorado. The Colorado uses an axle tube that is 3-3/16" diameter (compared to 2-3/4" on an S-10 Truck, or 3" for most full-size trucks).

The Stealth Conversion's U-bolts are made from 9/16" diameter steel, instead of the 1/2" diameter normally used by other manufacturers. The 9/16" diameter U-bolts cost more than the 1/2" diameter U-bolts, but they are much stronger and they can be reused, unlike the 1/2" diameter U-bolts which often fail when installed more than once.

The "Hi-nuts" used on the Stealth Conversion's U-bolts are much longer than normal nuts, and they resist stripping far better than normal nuts.

Torque our U-bolts to 85 lb-ft.

Since the 1/2-inch block works to increment the other sizes or bolts directly to the leaf spring using the original S10 U-Bolts, it does not include a Stealth Conversions U-Bolt.


The Stealth Conversions lowering blocks are unique in that the top of the block is threaded. This allows the pinion alignment shim to attach to the lowering block, while leaving the full height of the cap screw for the rear-axle locating hole.

Pinion alignment shims for the Colorado are available from Stealth Conversions.

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