Got a 1999-2006 Chevy or GMC pickup that you’ve had for a while? Chances are that your NBS (new body style) GMT 800 truck requires a suspension overhaul like this ’99 GMC Sierra did. After some intense online search and digging, we found just what we were looking for in an Aldan American 300219 Suspension Package.

Aldan’s new easy-to-install, bolt-on suspension kits for ’99-’06 Chevy Silverado and GMC Sierra 1500s are the latest in the company’s Road Comp Series. Everything is included in the kit, and it allows you to use factory or aftermarket control arms and the stock rear shock mounts. Infinitely adjustable front coilover shocks will lower the front of your truck from zero-2 inches, and the TruLine series adjustable rears can be tuned as well.

We recommend that you measure the ride height of your truck prior to getting started with the installation. Find a level spot to park and do your measurements. Complete instructions on how to measure the ride height and what discrepancies could mean can be found on Aldan’s website.

A product right out of the hotbed of high performance in Southern California, Aldan American is out to define a new standard ever since being founded in 1981. Formulated for street performance, vehicle-specific applications and racing, all of its shock absorbers, coilovers and suspension kits are designed, tested and made in the U.S., backed by a limited lifetime warranty.

Interested in our impression after the installation was completed? We couldn’t ask for a better riding, smoother-handling truck. Now let’s check out how it’s done!

First thing we did was measure the ride height of our truck on a level spot. Instructions on how to measure the ride height and what discrepancies could mean can be found on Aldan’s website.

Aldan American Suspension Package.

All the parts were laid out and checked against the list in the instructions prior to starting.

Apply the parking brake, then jack up the front of the truck, supporting it under the frame rails using jack stands. Here’s the front end with the wheels removed.

Gripping the shock with one hand, remove the upper shock nut.

Loosen the tie rod at the spindle and break it loose by hitting the side of the spindle at the steering arm. Don’t hit the tie rod threads.

Unbolt the brake caliper, hanging it out of the way using wire or a bungee cord. Don’t allow the caliper to hang by the brake line.

After taking out the cotter pin, the upper and lower ball joint nuts are loosened. Hit the spindle to break the joint loose. Once free, the nuts and spindle can be removed.

Remove the nuts at the top of the factory shock, then the bolts attaching the shock to the lower control arm. Now pry the front spring out from the lower control arm.

The shock nuts can then be removed from the lower control arm.

Copper anti-seize, a thread lubricant, is applied to the coilover shock.

The thrust bearings are greased before installation between the spring and the spring seat. This allows for easier adjustment since the spring seat is rotating on a bearing.

Here’s where the springs and the front shocks come together.

Install and tighten the new Aldan American lower shock brackets.

Position the Western Chassis’ drop spindles in the upper and lower control arms. Don’t forget to use the supplied cotter key. Torque the wheel bearing in place before installing the upper ball joint.

Unlike some kits, we didn’t need to cut the backing plate. You can just torque the wheel bearings and install the upper ball joint.

Tighten the upper shock nut but be careful not to over tighten them. Final tightening should be done with the wheels on the ground. The bushings should have a slight bulge.

Aldan American Suspension Package.

This is the front end completed, with the Aldan American coilovers installed.

Last to go on are these 20-inch Niche wheels. If you are running 17s, you may need to trim the stud on the lower ball joint or replace the OE stud to avoid any clearance issues.


Before we get going on the rear suspension, note that the stock axle runs below the springs.

Create a cardboard template of the Western Chassis C-notch, so that you’ll be able to transfer where we need to cut the frame rail, and drill holes in it.

Use a scribe or a Sharpie to show where the C-notch needs to be cut and the holes drilled.

With a cutoff tool or angle grinder, the C-notch is cut into the frame.

Holes drilled and the C-notch in place, this is how it should look.

Aldan American Suspension Install

Using jack stands, or if you have access to under hoist support stands, support the rear axle as you unbolt the stock U-bolts and remove the rear springs. With the springs out, use a vise to remove the U-bolt plate and bolt, replacing them on the opposite side (top).

Place the leaf spring under the axle and bolt them to the frame.

Insert the new saddles supplied with the kit under the axle and atop the springs.

Aldan American Suspension Install

Using the new U-bolt bottom plate, tighten the new U-bolts.

The Aldan American TruLine Series adjustable shocks are bolted into place on both sides, and we’re done.

Aldan American Suspension Install

This is how the rear shocks look when the installation is completed.

’99 GMC Sierra NBS looking good, with Aldan coilovers up front, TruLine rears and a Western Chassis C-notch.