Emissions Friendly Upgrades for the 2020 Duramax

After a few months’ hiatus from the magazine, this 2020 Denali Duramax project is back and slated for some awesome upgrades to continue with our original plan in showing readers what kind of emissions friendly modifications are out there for this all-new body style from the GM camp. There is no doubting or argument coming from us on just how great this latest L5P Duramax is, especially now backed by that incredible 10-speed transmission. The L5P Duramax is a definite performer and GMC really knocked it out of the part with the styling and overall look, but that mean there still isn’t a little room for improvement. Whether you’re looking to just set your stock truck apart from the next, add a little extra horsepower, or just dial it in to be more purpose built to your needs, what would ‘Project Seeing 2020’ be without some upgrades to make it look better?

While the Denali model trucks look pretty incredible pulling off the dealer lot, like anything, there’s always room for improvement. To help set this truck off the right way new set of wheels and tires were in order, but thanks to GM’s nearly square fender shape, to go any larger on tires also meant a leveling kit was going to be needed.

The factory Denali trim sets this truck off quite nicely, the addition of some extra chrome around the front-end and the polished factory 20” wheels definitely make a statement, but for the owner of this truck, it wasn’t quite the statement he wanted to make. As a stainless steel TIG welder by trade, this truck spends its weekdays dragging a large trailer from jobsite to jobsite and its weekends taking the family to the mountains camping. Living in Utah, the truck sees just about every weather condition throughout the year and dealing with snowy roads and muddy jobsites means traction is vital for getting around safely. While the factory Goodyears are a great tire, our owner wanted something a little more aggressive off-road without giving up its great highway and towing manners.  He also liked the idea of changing up the overall look on the truck by ditching the polished wheels with something more unique and a customed to his off-trail lifestyle.

The owner of this truck uses his rig daily for towing a large, enclosed trailer loaded down with steel and TIG welding equipment and on weekends it’s used for towing a large toy-hauler fifth wheel trailer, so he didn’t want to go to much bigger than stock, so the ReadyLIFT 2” leveling kit system was the perfect answer. With a simple torsion key swap and some drop spacers for the front differential, it’s a super easy installation to add clearance for up to a 35” tire.

Anthem Off-Road Wheels

Sticking with the hardworking, blue collar, life in the mountains lifestyle this build was just begging for a set of Anthem Off-Road wheels. Anthem is a small hometown type company based out of the mid-west, that builds wheels specifically for hardworking truck owners like themselves. The Anthem logo and way of life pays tribute to the military, first responders, and patriots of our country and they stive to offer the best customer services and best relationship they can with all their customers. Anthem designs their own wheels in-house, but also offers complete tire/wheel packages that come shipped for free, mounted, and balanced ready to install on the truck.

Anthem Off-Road has really come on strong the last few years with some great looking and super durable wheels for the light duty truck market, and their brand-new 20×9 Rogue in with it’s gloss black sheen and machined edges was the perfect look for this build. The simulated bead lock edge offers an aggressive off-road feel while still offering up that stylish look the owner was after.

For 2021, Anthem released the all-new Rogue, which is a traditional off-road looking 8-spoke wheel that looks great on just about any truck. Offered in gloss black/milled (like we opted for in 20×9), matte black and even a bronze color, the Rogue was designed to not only look great but be functional as well. The Anthem hubcap piece uses a bolt-in logo that can be removed and painted to fine tune your overall look the way you want it. And the simulated bed lock ring around the outer edge of the wheel has removable bolts that can also be painted, or powder coated the way you like it. The biggest bonus to the removable outer bolts, however, is their ability to protect the wheel lip from curb rashes and scuffs. So, if you accidently rub your wheel against a curb, no need to cringe or cry, the stainless bolt heads will take the abuse, not the wheel. So, you’re just a couple of replacement bolts away from having a perfectly undamaged wheel. Genius.

The 295/60R20 Open Country A/T3 from Toyo was just what we needed to fill the wheel wells of this GMC. Right at 34” tall (similar to the factory 275/65R20) it would clear without rubbing anywhere on the bumper or inner fender liner, while adding some extra width for a more aggressive stance.
Just a tech tip, when you get your new wheels, it’s always a good idea to install them, just as a test fit run before the tires have been mounted and balanced just to make sure you don’t have any clearance issues anywhere. Besides, it gives you that first glimpse of just how great your truck will look by morning.

Toyo A/T3

It’s been a little over a year now since Toyo released the latest version of their Open Country A/T, the A/T that incorporates everything they learned for the extremely popular A/T 2, but with even better off-road traction and on-road grip. The engineers behind the A/T3 really focused on the tires performance in wet conditions and improving treadwear and durability to offer the absolute best all-terrain they could. As an all-terrain tire, buyers usually look for a tread pattern that is good at just about everything. It doesn’t really need to excel at one specific thing, but it absolutely can’t fail at anything either. The Toyo A/T3 is really a culmination of years of testing and development that doesn’t just do everything ‘good’ it’s proven itself to be great just about everywhere you’ll take it.

First step to the leveling kit install is removing the factory front shoch absorbers and installing the supplied shock spacer bushings on the mounting studs. Since we’re dealing with a virtually brand new truck here there was no reason to replace the factory shocks and the ReadyLIFT kit allows you to reuse them saving some expense.

Snow traction has been excellent with the factory multi-wave sipes, which also help reduce irregular wear and extend tread life. The new tread pattern is super quiet on the highway and has great braking and cut/chip resistance as well. We’ve only had the tires on this truck for a couple hundred miles, but you can bet we’ll report back in a few months on their tread wear and performance and the miles continue to rack up towing that welding trailer around. This truck had a 275/65R20 under it from the factory, which works out to be a narrow 34” tire. Not wanting to go any taller, we opted for a 295/60R20, which is still 34” tall, but over an inch wider than stock for a little extra tread on the ground and a little more aggressive stance. Thanks to GMC’s nearly square fender design, this subtle change does require a slight lift front to gain clearance around the bumper and inner fender liner on the 2020+ trucks.

Like virtually every independent front-end GM truck before it, this latest 2020-2021 body style truck uses a torsion bar for its front suspension, and simple re-adjusting that torsion bar with new torsion keys will help take care of the extra height we’re after.


Again, since this truck is used daily for towing, the owner didn’t want to go any taller than stock, as keeping the bed easily accessible was important to him, so a simple leveling kit was all that was needed. The truck sat about 2” taller in the rear stock, so bringing that front-end up to match would be perfect for this wheel/tire package. ReadyLIFT’s kit for the new 2500HD and 3500 trucks includes everything you need to complete a simple front suspension level with the addition of their new torsion keys, front differential drop and shock spacers. This install only took about an hour and was completed in the garage with nothing more than basic hand tools and ReadyLIFT’s special torsion key removal tool you can purchase online when you order the leveling kit.

Using a special torsion key tool you can source directly through ReadyLIFT when you order your leveling kit, this installation is straight forward and easy enough a shade tree mechanic should be able to tackle it in their garage. There are great instructions included, along with some step-by-step instructional videos on the ReadyLIFT YouTube page.
With the factory torsion keys removed you can compare them to the new ReadyLIFT keys. While to an untrained eye you may think these are the same, the new key will rotate the torsion bars at a slightly different angle, which creates the added lift we need to get the truck sitting level.

Most leveling kits for the GM trucks will just replace the torsion keys to get you that extra inch or two of lift, but ReadyLIFT goes the extra mile to make sure the suspension geometry stays within spec. The included front differential spaces allow the differential to be dropped down slightly from the frame, so your four-wheel drive axles stay at a safe angle, so you don’t add any undue stress and premature wear. The kit also keeps the lift budget friendly by allowing you to reuse your factory shocks with some added spacers as well. ReadyLIFT does offer some taller lift options like their SST kit and full blown 6-8” suspension lifts, should you decide some 37” tires need to go under your truck, but for this owner, the mild 2” up front was perfect and left plenty of clearance for the new tire and wheel package.

Along with the torsion key swap, ReadyLIFT also supplies some machined spacers to install between the chassis and your front differential. With the added suspension height, the factory front drive axles can be placed at a much steeper angle, which can lead to premature wear and failure. The diff drop keeps those angles at factory specs, so you’ll see no ill side effects from the leveling kit installation over time.


Finally, for this month’s upgrades is the addition of a tonneau cover. Living in a climate where you see all four seasons, with no particular rhyme or reason, being able to keep the stuff in your bed safe from the elements is a major plus. The Access Lorado bedcover from AgriCover is one of those upgrades you’ll always wonder why you didn’t install sooner. They fit incredibly well and look incredible. The fabric used is tough, durable, and won’t fade over time in the sun and the cover has easy adjustments to make sure it stays tight over the years. In the first article on this 2020 Denali, we installed emissions friendly performance upgrades like the MBRP DPF-back exhaust and high flow intake tube and turbo inlet from Wehrli Fabrication. Next month we’ll continue you down that road with more horsepower from the all-new Pulsar with CTS3 Insight package from Edge Products (spoiler alert: it adds up to 136hp/293tq to the tires with power levels adjustable on-the-fly). We’ve also got a new fuel filtration kit from Extreme Filter Housings and some more airflow upgrades from WC Fab.

There were four mounting points for the differential to the frame, and it only took an extra 30-minutes in our install to have the spacers installed and everything torqued back to spec. It’s little things like this that make ReadyLIFT one of the top suspension companies in the market today, sure there are ‘cheaper’ leveling kit options out there, but cheaper doesn’t mean better. ReadyLIFT goes the extra mile to make sure everything is done right.
Mounted up on the new Toyo rubber, our Anthem Rogue wheels really helped set this truck apart. The change from the factory polished wheel to this gloss black and machined wheel makes such a dramatic statement.
The 20×9 wheel and 295/60R20 tire size fit great under this GMC with just the right offset to add a little width and more aggressive styling, without giving us too much tread outside the fenders risking more rock chips and mess as we rack up the miles on this truck.
Living in Utah, a state that sees all four seasons, having the tread pattern to conquer everything from slick snowy winters, sloppy, muddy springs, and hot desolate asphalt highways, choosing the perfect tire was a no brainer. The latest Open Country A/T3 from Toyo Tires has proven to be a near perfect tire for that owner that needs his truck to be good at just about everything.
A good tonneau cover will be one of those things you never regret adding to your truck. The Lorado Access cover from Agricover has been a staple in the soft roll-up tonneau market for a long time and for good reason. The install is super easy with just a few bed clamps and they fit like their factory equipment.
With the supplied outer bed rail brackets installed on the truck, installing the supplied gasket along the front edge of the bed will ensure a watertight seal when the bedcover is pulled tight and closed. The Lorado cover an excellent upgrade for both cosmetic and protection reasons.
Access uses this super simple quick adjuster to allow you to fine tune the bed covers fit, you can adjust so the bedcover stays tight and wrinkle free, which will cut down on wind noise help keep everything sealed up tight inside the bed. It’s also worth noting, this cover worked perfect with the new GMC multi-pro tailgate.
It’s honestly one of those modifications you’ll make to your truck that makes you ask yourself why you haven’t owned and installed one sooner. The Access roll-up cover fits nice, still allows you to use the entire bed and even tow your fifth wheel trailer when you need to, without breaking the bank.
With the supplied outer bed rail brackets installed on the truck, installing the supplied gasket along the front edge of the bed will ensure a watertight seal when the bedcover is pulled tight and closed. The Lorado cover an excellent upgrade for both cosmetic and protection reasons.


Anthem Off-Road

Toyo Tires



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