SUBURBAN DENALI HD
nine-passenger seating, but was in running and drivable condition even if it was a little rough around the edges. The original plan was to simply swap in the Duramax and Allison drivetrain then paint the Burb GM Arrival Blue and enjoy the new shop SUV. They drove the Burb for about a month while ordering and waiting on parts to come in for the swap. Virtually all of the drivetrain components came from the team at Hicksville Auto Recyclers in Hicksville, Ohio, where their team specializes in Duramax trucks and parts with everything from complete trucks to small components. To make the swap possible, the team purchased the engine, transmission, transfer case, various mounts and a complete LTZ interior including the dash, seats, door panels and center console.
Physically getting the Duramax engine and Allison transmission into the Suburban 3/4-ton chassis was actually pretty simple. It dropped right into place after they swapped out the gasser engine brackets for a set of diesel engine mount brackets and moved the transmission crossmember about an inch. But to use the core support, radiator and intercooler from a diesel truck and to clear the turbo on the top of the Duramax the Suburban body need-
ed to be raised by 2 inches with a body lift. Rather than buy an off-the-shelf lift, the team at Merchant Automotive fabricated new brackets in house to raise the body and still use factory body mount bushings. While they were working on the rusty chassis components, the project took a turn that would completely change the scope of the build. Merchant decided he wanted to build the Suburban to be “like new,” as he felt GM should have originally built it.
With that new design direction in mind, the team completely stripped the chassis down, including every component of the running gear, and sent everything over to the team at ND Collision in Hamilton, Mich., where everything was blasted down to bare metal then coated with Dupont Industrial Coatings gloss black finish to not only look great but also handle the harsh Michigan weather. While putting everything back together they installed new polyurethane bushings from Energy Suspension and ultrasonically cleaned all the hardware, then had it zinc plated, before reinstalling it.
In addition to fully restored original chassis components, the team installed upgraded Bilstein 5100 series shocks at all four corners for a smooth ride. To address the weak
points in the GM IFS they installed Cognito upper control arms and steering braces, as well as their own MA stainless steel tie rod sleeves to keep the SUV pointed in the right direction. To improve the braking capabilities of the big Duramax-powered SUV, Merchant opted to go with a set of Wilwood Tactical Series brake kits for the front and rear of the truck. The brake upgrade is a serious one, with enormous 16-inch diameter brake rotors at all four corners and equally substantial six-piston brake calipers and performance brake pads to stop the rig with authority.
While the chassis work was being completed the MA team turned its attention to the Duramax engine and Allison transmission, since putting bone stock units in the truck wouldn’t give the truck the oomph it deserved. The LMM from the Hicksville Auto Recyclers donor truck was torn down and Mahle Motorsports pistons with gapless rings were installed on stock rods that are swung by the stock crank. The factory camshaft was replaced with a SoCal Diesel 3388 camshaft for a little more performance. The heads were bolted back down with a set of ARP head studs to keep them securely on the block and keep the combustion charge inside the engine. The crankshaft received a Socal dampner on the front side and a BD Diesel flexplate on the back side to link to the Allison transmission.
ATS Diesel Performance exhaust manifolds and up-pipes channel spent gasses out of the engine up to a Stealth 64 VGT turbo from Duramax Tuner. A modified MBRP downpipe channels the exhaust gasses out of the turbo through a 4-inch MBRP exhaust system and Walker heavy duty truck muffler to keep the exhaust note down to a minimum in the plush SUV. Fuel is delivered from the factory tank through a FASS fuel pump and filter system up to an Engineered Diesel 10 mm CP3 high pressure pump. From there, a set of 45% over injectors from S&S Diesel Motorsport deliver the fuel into each cylinder.
On the intake side, the LMM draws in fresh air through an S&B Filters cold-air intake. Clean air is then compressed
by the Stealth 64 VGT and sent to a factory GM intercooler through a set of fabricated and powdercoated Merchant Automotive boost tubes. As the intake charge returns from the intercooler it is channeled into a stainless Y-bridge from Adrenaline Performance and sent down into the engine. With Duramax Tuner cycling the 1s and 0s in the ECU via EFILIVE tuning, the truck is very drivable and has delivered 665 horsepower and 1,275 lb-ft of torque to the rear wheels on the chassis dyno.
The powerful LMM Duramax is linked to the Allison transmission through an ATS Diesel Performance Five Star torque converter to handle the power without slipping. Of course, a stock Allison would not handle the power either, and since Merchant Automotive specializes in building performance Allison transmissions they rebuilt the donor transmission to their Maximum Pro Series standards. It uses improved clutches and steels as well as hydraulic upgrades to handle additional power. The donor truck’s original MP1626 transfer case is used to split the power to the front and rear axles through custom driveshafts built by D&R Driveline.
Paint and bodywork was left to the pros at ND Collision, who did much more than just respray the body. The Suburban’s shell was completely stripped and gutted, then massaged to perfection. Even the complete roof panel was replaced for sheet metal with a factory sunroof opening so Merchant could have a sunroof in the SUV like other fully-loaded models. Additionally, they replaced all four doors with new metal and perfectly aligned everything. A Cadillac Escalade hatch was used In the rear, along with a Chevy rear bumper with parking sensors, while the front end was treated to GMC Yukon Denali body panels including the grille, bumper, hood and fenders. Once everything was completely straight and smooth, they sprayed it in Merchant’s favorite color, GM Arrival Blue, and buffed and polished it to perfection. Inside, they sprayed a coating of Line-x spray-in bedliner throughout the body shell to further reduce outside noise.
When assembling the interior, Merchant and the MA team used a combination of new and good used parts to give the SUV an LTZ appearance with leather seats, the slick LTZ dash and console, and of course a factory sunroof. They also integrated additional factory options including power-adjustable pedals, power rear liftgate, integrated trailer brake control, dual zone auto climate control, steering wheel controls with heat, and heated memory front bucket seats to replace the original front bench. They even went as far as installing factory remote-starting capability and rear collision avoidance parking sensors to wrap up the package.
But again, Merchant wanted his Suburban to be as good as or better than the factory high-level models, so he also installed a high-end aftermarket audio system. It starts with an 8-inch touchscreen Alpine X008U navigation receiver that fits perfectly in the factory LTZ dash panel. Audio signals route to a pair of JL Audio amplifiers with a JX500 powering the 10-inch JL Audio Stealthbox subwoofer installed in the factory center console location, and a JX360 4-channel amp installed behind the rear driver-side interior panel to power front and rear JL Audio CS650 component speakers installed in each door.
To wrap the swap project up, the team installed a set of highly polished 22x10-inch American Force Hero wheels wrapped in Hankook 305/45R22 Dynapro ATM tires. The huge wheels were needed to clear the massive Wilwood brake upgrade, while, of course, they also give the truck a great look and stance. Slight clearance at the corner of the front bumper was necessary to keep the tires from rubbing while turning sharply. Since the SUV sits rather high, they also installed a set of Amp Research power side steps to make it easier to get in and out of the rig. The only exterior badging that the truck retains is the GMC logo in the grille and a custom MA logo that was machined to fit in the void left by removing the Cadillac emblem in the rear.
Starting with a run-down, plain white 2008 Chevy Suburban, Eric Merchant and his team at Merchant Automotive completed a stunning and complete transformation into the Suburban Denali HD you see here in a two-year process that resulted in a better-than-new SUV, and one of the best Suburban’s we’ve ever seen. We’re sure they could have completed a basic Duramax swap in much less time, but the results wouldn’t be as stunning or as satisfying. Merchant and team wanted something that GM wouldn’t build—so he and his team built it themselves! UDBG
The rear of the chassis is just as clean as the front, with the refinished AAM 10.5 rear axle and factory 3/4-ton leaf springs getting help from Sulastic shackles and Air Lift airbags to help the rig tow anything that Merchant needs. He also installed Bilstein 5100 series shocks on all four corners, and you can see the MBRP exhaust system and polished stainless steel tip here as well.
While Merchant had the Suburban on the hoist to polish the wheels before our photo shoot, we crawled under the truck to take a few shots of the unbelievably clean chassis. The old chassis components were stripped and painted gloss black and/or replaced with new components that were also painted gloss black. The results are a chassis that looks better than any that rolls off the GM assembly line.
A Wilwood Tactical Series brake kit is installed up front complete with gargantuan 16-inch rotors that are clamped down on by six-piston Wilwood calipers to bring the big SUV to a stop in a hurry.
As one of the premier Allison transmission builders in the country, Merchant and his team gave the transmission their Maximum Pro Series treatment, with upgrades throughout to handle the stout Duramax that now resides under the hood.
The rear brakes also received a Wilwood Tactical Series upgrade, with another set of gargantuan 16-inch diameter rotors and massive six-piston calipers to join the fronts to make sure this rig can slow down any load it’s hauling.
The Duramax inhales fresh air through an S&B Filters cold-air intake system before handing it off to a Stealth 64 VGT turbo from Duramax Tuner to build some boost. Matching powdercoated boost tubes that the MA team fabricated channel the high pressure charge from the turbo through the intercooler and back into the engine.
The factory intake muffler has no place on a performance engine. Fortunately, Merchant Automotive makes the proper block-off caps, so the team installed their own off-the-shelf products on the Suburban.
Lifting the Denali hood reveals a 6.6L LMM Duramax engine that should have been an option on the 3/4-ton SUV direct from GM.
Merchant prefers the look of the GMC trucks and SUVS over their Chevrolet siblings, so he swapped the front grille, bumper, headlights and sheet metal, including the hood and fenders, for Yukon Denali parts before they were slathered in bright GM Arrival Blue paint by the team at ND Collision.
Looking at the finished Suburban, you can see the amazingly clean finish with no body moldings or emblems to mess up the smooth lines. It’s hard to see, as the glass blends into the paint, but the factory sunroof is barely visible in the roof, which has also been stripped of the traditional roof rack and associated hardware.
The same 22-inch American Force and Hankook wheel and tire combination is also carried to the rear of the Suburban. Also notice the 5-inch polished stainless steel MBRP exhaust tip that exits in the factory location.
Large wheels are required to fit the big Wilwood Tactical Series brakes, so Merchant opted for a set of highly polished, forged aluminum, 22x10-inch American Force Hero wheels wrapped with 305/45R22 Hankook Dynapro ATM tires for sure grip in any conditions.
To keep an eye on the Duramax engine’s vitals, Merchant relies on an Edge CTS2 display that delivers precise measurements through additional sensors to directly monitor EGT, boost, intake temperature and lift pump pressure, in addition to the standard OBD data it can display.
Merchant even integrated the power lift gate mechanism for push button control of the rear hatch to open up the Suburban for storage, or the 3rd row seating if more space is needed. The four-channel JL Audio JX360 amplifier is installed behind the driver-side rear panel, out of sight but not out of mind when the tunes are cranked.
The heart of the audio upgrade looks nearly factory, with the large 8-inch display of the Alpine X008U multi-media receiver perfectly fitting in the confines of the factory LTZ dash panel.
Suburban taillights and bumper cover with integrated parking sensors are used to round out the rear of the MABURBN.
He used a Cadillac Escalade hatch, along with the full-width LED third brake light, to give the Suburban a real touch of class.
Rather than sticking with the Cadillac emblem, the Merchant Automotive team machined a billet aluminum MA logo to fit in the same location, along with painted accents.