Subscribe to the Free
Newsletter
  • |
  • |
  • 2003 Chevrolet Silverado: Mike Maas’s 1,200hp Duramax Shop Truck Is A Streetable Beast

2003 Chevrolet Silverado: Mike Maas’s 1,200hp Duramax Shop Truck Is A Streetable Beast

1,200 Horsepower Shop Scorcher

Brian Lohnes
Oct 30, 2017
Photographers: Alex Bellus
The shop truck is an American institution. Every small garage, performance based business, machine shop, or hot rodding enterprise has a vehicle that gets used to gather parts, grab lunch, zip across town, or pick up necessary pieces from vendors. Most of them don’t have 1,200hp like Mike Maas’s does, though. Mike has built himself an awesome 2003 Chevrolet Silverado (that wears a 2005 grill and hood) which not only makes massive power but also has the right driving manners to make it the perfect shop truck for his business Dark Horse Diesel Performance in Watkins, Minnesota.
In a world dominated by pickups that have three and four doors, why did Mike choose to pour all of this power into a regular cab truck? The answer was quick and simple. “I’m a regular cab guy,” he said. “There’s something about the regular cab trucks that I have always liked. Back in the day that was the only option people had. When I think of a pickup truck my first thought has always been a regular cab and that’s why I had to build this truck the way that I did.”
So if we know why he likes the regular cab trucks, then why is it this particular era of regular cab trucks Mike has keyed in on? “LB7, baby,” he said with a laugh. “I think I have owned seven LB7 trucks over the years and I have found them all to be great. Heck, both of my kids are in LB7 trucks and I actually have a couple more of them myself.” Yeah, Mike is committed we’d say.
The truck’s evolution from mildly modified cruiser to 1,200hp muscle car slaying monster took the same kind of gradual ramp at first that many of these stories do but as more power was gained, Mike wanted more power added. The result is a rig that will walk a modern “super car” like it is tied to a tree stump. The best part is that the truck can do the job while keeping the passengers in comfort. “I have a 500hp gas V8 swapped S10 truck that I built years ago and it’s pretty fast but I barely ever take it out anymore,” Mike explained. “It’s hot, it rattles, and it’s just like an old school hot rod. The truck has all the modern comforts in it. I added the factory steering wheel controls, a good stereo, it has air conditioning and it even will knock down mileage in the high ‘teens on the highway when we take it on trips. You literally cannot beat it.”
Yes, we mentioned taking this four digit horsepower making rocket on long trips because Mike drives it everywhere. “I’m not kidding when I tell you that this is my go-to truck for everything. We use it to drop parts off at the machine shop, we use it to go get groceries, we use it and treat it like any other stock truck. It runs great on regular fuel out of the pump just like a stocker,” Many big horsepower street trucks do not have this user friendly nature. Whether they are really laggy, lack responsiveness, or are just plain peaky to drive, they aren’t something that anyone can just hop into and understand how to operate properly. This truck defies all of that because of the smartly built engine. Let’s see how it was done.
Using a stock LB7 bore block with a balanced stock crank, Carillo connecting rods, MAHLE Motorsports cast debowled pistons with valve reliefs and 16.1:1 compression the next step was selecting a camshaft. Craig’s Machine and Dyno came up with a custom firing order camshaft that moves the valves in a set of Wagler Competiton Street Series cylinder heads. While those hard parts make up the foundation of the engine, the meat of the combination comes together when we talk about the induction and fuel systems. HSP Diesel plumbing ties a Borg-Warner S485 atmospheric turbo to a Borg-Warner S369SXE valley mounted turbo. HSP supplied the billet wheels for the turbos as well as the exhaust manifolds used for moving the spent gasses. On the fueling side, S&S Diesel Motorsport 150% injectors fire the fuel into the engine and are fed by a Pacific Performance Engineering dual fueler kit spinning a stock LB7 and a stock LMM pump. Interestingly, that kit uses a custom wheel built by Wold Fabrication that matches the actual wheels on the corners of the truck! A FASS Diesel Fuel Systems 220 lift pump pulls fuel from a stock tank that uses a custom sump made by Wold Fabrication. When these parts and pieces are combined with EFI Live tuning by Danville Performance, the final result is 1,244hp and a truly astounding 2,193 lb-ft of torque. You want a piece of this rig? Come and get it!
We didn’t want to offend Mike when we told him that his truck didn’t outwardly look like a 1,200hp machine but frankly it doesn’t hurt his feelings at all. The good news is that he intended it to be just exactly as it is and it made him happy to hear that we thought it was a sleeper. “If you really look at the truck you can see that I built it with anything that looks racy kind of hidden,” Mike explained. “There are no gauges on the pillar and there’s really nothing that you can see from the outside that gives it away. The exhaust is a straight pipe that dumps at the axle because I have the roll pan in the rear and I didn’t think a tip would look good under it.”
Getting the truck to sit at the right height was also important to Mike, “My favorite thing about the truck is its overall look,” he said. “I think the truck sits just right. Some guys put the trucks down really low and there are issues with stuff rubbing or you have to do things that I don’t like to make it work. Wold Fabrication custom made the traction bars, we lowered the back with three-inch drop shackles. Up front we moved the mounts two and a half inches and used lowering keys for the torsion bars.”
Sure, Mike Maas may not have the storage room that an extended cab or crew cab truck owner has but he does not care. Instead he has his dream truck and unlike many people who “get what they wished for” and regret it, Mike revels in how much he is able to use his truck. If there’s one thing we know about shop trucks it’s that they never stay the same for that long. Mike Maas has 1,200hp now but who knows how much he’ll have in the future. While we may be uncertain about that, we’d be willing to guarantee it’ll be wrapped in the nose of a regular cab truck and no one will be able to see it coming!
Fast Facts

Year/Make/Model: 2003 Chevrolet Silverado

Owner: Mike Maas

Hometown: Watkins, Mn

Odometer: 304,000

Engine: 6.6L Duramax stock stroke, stock bore, Carillo rods, Wagler Competiton Street Series cylinder heads, BD Diesel flexplate, ATI dampener, balanced stock crank, keyed crank and cam by Wold Fabrication, custom ground stock firing order camshaft from Craig’s Machine and Dyno in Litchfield, MN, MAHLE Motorsports cast pistons debowled with valve reliefs, 16:1.1 compression Danville pinned water pump, SoCal billet injector hold downs, SoCal glow plug delete Programming: EFI live by Danville Performance
Fuel: S&S Diesel Motorsport 150% over injectors, PPE dual fueler kit with custom wheel from Wold Fabrication, stock LBZ and LMM fuel pumps, Fass 220 with 5⁄8 feedline, Wold Fabrication dual outlet fuel sump.
Air: Borg Warner S369SXE valley mounted turbocharger charger, Borg Warner S485 atmosphere turbocharger, HSP Diesel billet turbocharger wheels, HSP diesel exhaust manifolds and 2 1⁄4-inch up pipes


Exhaust: Owner built, 4” downpipe to 5” straight pipe with axle dump


Transmission: Allison six speed automatic with Limitless Diesel Performance trans kit, Custom Suncoast converter from Limitless Diesel Performance, transmission assembled by Harris Performance Transmission in Morris, MN.
Lubricants: Mobil Delvac 15/40 engine oil, Dexron 3 ATF Fluid
Power:1244 hp

Torque: 2193

Tires: Nitto 305/50/20 420S
Wheels: SOTA Off Road 20x10 with-19 offset


Suspension: 3” drop shackles, relocated front mount that was moved up 2 1⁄2”, lowered keys in the front, custom traction bars by Wold Fabrication
Axles: Stock with Dodge carrier

, stock 3.73 gearing
Body: Stock with 05 hood and grill swap, color matched roll pan, LED tail lights, front valance and factory fog lights

Interior: Cloth with center console swap, added power drivers seat, added steering wheel controls

POPULAR TRUCKS

Subscribe Today and Save up to 83%!

Subscribe Truck Trend Magazine

Subscribe to:

Truck Trend
Magazine

PRINT DIGITAL
Subscribe Diesel Power Magazine

Subscribe to:

Diesel Power
Magazine

PRINT DIGITAL
Subscribe Truckin Magazine

Subscribe to:

Truckin
Magazine

PRINT DIGITAL
SUBSCRIBE TO A MAGAZINE
CLOSE X
BUYER'S GUIDE
SEE THE ALL NEW
NEWS, REVIEWS & SPECS