Big Red Part IV: Dually Lift Install

Updated Apr 3, 2015

Big Red Dually Beauty_BS28354Gaining Ground:A six-inch suspension lift kit and rear air bags pave the way for 35s and big-rig-style, 10-lug wheels on our GMC Dually project truck

By Bruce W. Smith

A small crowd of pickup owning-customers standing in the Truck Supply and Outfitters shop bay door started moving back and pulling out their smartphones as the last lugnut was cinched down.

Big Red was about to roll out where everyone could get a picture.

The buzz started the day before when Daniel Parker and David Adair, the two TSO installers who have been upfitting our project truck from day one, started on Big Red’s biggest change – a six-inch Cognito suspension lift.

But the lift alone wasn’t creating the excitement as a fair number of the heavy-duty pickups that roll in and out of the TSO shop in Tuscaloosa, Alabama, are running suspension kits.

It was the combination of the lift and the tire/wheel package going on with it that everyone wanted to document for their Facebook and YouTube accounts.

The wheels we chose for Big Red are American Force Combat 22s, forged aluminum beauties with the big-rig 10-lug bolt pattern, are more than capable of handling the heaviest of loads a GMC Sierra 3500HD Dually would ever be tasked with in the construction world.

Wrapped around the black 22s, 35×12.50R22 Toyo Open Country M/Ts that set off Big Red like no other combo we’ve seen.

Our crowd of appreciative onlookers, some of which own their own construction companies, seemed to agree as smartphones clicked like they were taking shots of some celebrity.



These types of lift kit installs aren’t for the typical fleet’s shop mechanics;they take a lot of time – and certain level of expertise to do them right. And, bigger lift kits are not a ­necessity for every fleet’s 4×4 dually field-service truck.

But the additional body height makes way for taller tires, which in turn provide more ground clearance. Contractors who have driven around off-pavement jobsites knows how valuable extra clearance between terra firma and the rear differentials can be.

We also wanted to give you some upgrade ideas that might be applied to your next truck – or an existing one.

That said, we called one of the premier suspension manufacturers around, Cognito Motorsports. Their lift kits are known for their premium quality and design.

The kit (FSLK100407) Parker and Adair installed under Big Red is Cognito’s non-torsion bar drop 4”-6” designed specifically for the 2001-2010 GM HDs with the IFS front suspension.

Keeping the torsion bars in the OE position helps retain the factory ride and handling.

New spindles, upper control arms, subframe brackets, Bilstein shocks, and a three-inch block for the rear leafs are also part of the package.

Cognito also upgraded Big Red with a heavy-duty front sway bar end-link kit, pitman/idler arm support kit and heavy-duty tie-rods. All components that are potential weak links down the construction road.

The installation of such a kit takes the skills and tools of a qualified shop mechanic and about eight hours. There’s no welding required. But you will use the sawsall a couple times

Once to cut the back of the driver’s side lower control arm frame pocket, and another cut off the top transmission mount once the trans is out of the truck.

(Cognito has replacements in case you want to go back to the stock suspension.)

The bright side is Cognito supplies about 30 pages of detailed instructions with photos just in case any questions arise along the way that need answered. (TSO installers have done a number of similar kits, so they breezed right through it.)

While the suspension was being redone we installed Hellwig’s Big Wig stabilizer bars, front and rear to minimize body roll/lean as the big Dually will be a little more top-heavy than it was stock.

A Hellwig Rear Air Suspension, which consists of an air helper spring over each side of the rear axle, was added as well.



You have to admit, American Force’s 10-lug wheels look really wicked on any heavy-duty pickup. Put them on a dually and now you turn heads.

We ordered them powdercoated gloss black with machined faces to show off the American Force name.

The lifetime warranty against manufacturer defects is also a plus when you are spending $5K for custom rims.

Of course, custom wheels are worthless without tires that look good and perform well. Toyo’s Open Country M/Ts do just that.



There’s no need to go into all the details of Big Red’s suspension upgrade in these pages because you can go to our website to see the step-by-step, or you can go to Cognito’s website to download the instructions.

But I do want to pass along a few tips, tricks and observations Parker made as they did the work. As the images on these pages show, these items can make the installation go easier if you plan on doing the same to your GM HD.


SPONSORS “BIG RED” Presented by Mobil Delvac


American Force Wheels:; 800-620-6259

AMP Research;;


B&W Trailer Hitches:; 800-248-6564

Barkley GMC:; 205-556-6600

BD Diesel Performance:; 800-887-5030

BOLT:; 877-251-8798


Buyer’s Products Company:; 440-974-8888

Fab Fours Bumpers:; 866-385-1905

Fleetwest:; 866-497-7200

Hellwig Products:; 800-435-5944

Husky Liners:; 800-344-8759

Hypertech:; 901-382-8888

Marathon Seat Covers:; 800-735-2769

Mile Marker:; 800-886-8647

Toyo Tires;; 800-442-8696

Transfer Flow:; 800-442-0056

Truck Supply & Outfitters:; 205-553-4203

USFLeet Tracking:; 405-749-1105

Vanair:; 800-526-8817




American Force Wheels:; 800-620-6259

Cognito Motorsports:; 866-426-4648

Hellwig Products:; 800-435-5944

Toyo Tires:; 800-442-8696

Truck Supply & Outfitters:; 205-553-4203