You don’t have to think too hard when you look at the regular cab/short box body style and the “GT454” designation at the leading edge of the rear fenders to figure out what inspired the creation of this late-model muscle truck. “Oh, it was totally the original Chevy 454SS from the early ’90s,” says Kelley Longwish, the performance manager for LaFontaine Automotive Group, a Michigan–based collection of dealerships that is a strong proponent of dealer-based high-performance. There is even a dedicated LaFontaine Performance Center and the dealership group backs several local drag racers. “There’s something elemental about using the most basic, lightest truck configuration and stuffing it with the most powerful engine you can put your hands on.”

There is indeed, and this super-tuned GMC Sierra absolutely evokes the spirit of the 454SS in its stance and attitude. However, it trumps its performance with about three times the horsepower and twice the torque from its Chevrolet Performance (formerly GM Performance Parts) LSX454 crate engine. The engine cranks out 626 hp and 628 lb-ft of torque, breathing through a factory truck intake manifold and throttle body. That’s comparable to the output of the Corvette ZR1’s supercharged LS9 engine, but without the heavy power adder.

Building the truck wasn’t an exercise in nostalgia, either. LaFontaine intends to sell the GT454 as a fully backed turnkey package. The store Longwish works out of is a Buick-Cadillac-GMC outlet, so he didn’t have access to a Chevy truck, but using the Sierra he wanted to turn into the GT454 wasn’t easy, either. Assuming he’d simply wade into the acres of Sierra pickups on the lot and have his pick of the litter, he was surprised to find not a single regular-cab short-box model among hundreds of trucks. “It is almost impossible to find a regular-cab short-box truck these days,” he says. “Although it was a common configuration years ago, nobody really orders them any longer. Turns out, we really don’t stock them, so we special-ordered it for this project.” The rarity these days of that body configuration make the GT454 stand out even more, in our opinion. You just flat-out don’t see them, as truck buyers have turned to extended cabs. By the way, the GT454 name was Longwish’s idea to blend the “GT” designation that was used years ago on some GMC trucks with the “454” of the engine and old 454SS name. This makes perfect sense to us.

Further distinguishing the looks of the truck is an APM Automotive ram-air hood, body-color grille and a rear roll pan, along with a Street Scene front lower fascia. There’s also an Extang tonneau cover and a Bed Rug. The new exterior components are complemented by a hunkered-down stance derived from a Belltech lowering kit that dropped the nose 4 inches and the rump 6 inches, matched with shocks that help maintain a surprisingly compliant and comfortable ride quality. Inside, the GT454 is about as basic as it comes from the factory, but at least it has carpeting and a radio. LaFontaine added leather upholstery with the dealership’s logo embroidered on the headrests, but if we could toss in our two cents, we’d suggest GT454 logos instead, as this dealer-built special is all about the engine.

Because all of the technicians at the LaFontaine dealership were busy wrenching on customer cars, the assembly of the truck was farmed out to Pratt & Miller, the company that runs the Corvette Racing program for Chevrolet, including building, maintaining and fielding the race cars. Pratt & Miller are also a great restoration/hot rod construction arm of the business that did all of the paintwork and installation of the new body parts, as well as the installation of the suspension components and engine. Motor City Speed handled the engine work and dyno tuning.

Kelley Longwish is the first to admit that building the GT454 was a gamble. Although it was the prototype and a few details may change with “production” versions, he suggests the target price for a customer who wants one just like it is in the neighborhood of $69,000. Considering that roughly $30,000 of that will be the base cost of the truck itself, the package doesn’t seem like such a financial stretch. “We don’t know what the appetite is for a vehicle like this, but it sure is fun to drive and gets loads of attention,” he says. “What’s great is that the LaFontaine Group is committed to performance and letting our customers help drive where we go with projects like this.”

That’s a great attitude and it’s encouraging to know there are dealers who still see the value in high-performance specialization. We’ll take the next one in black, please, with a red interior.

Inside the Build
Year Make Model:
2011 GMC Sierra

Owner and City/State:
LaFontaine Motors • Highland, Michigan

Engine
Type: Chevrolet Performance LSX454
Induction: Injen cool-air intake, 6.2L truck intake manifold, and 87mm throttle body
Exhaust: American Racing Headers 17/8-inch long-tubes and MagnaFlow exhaust
Camshaft: .635 lift with 1.8 roller rockers
Fuel System: Chevrolet Performance
Engine Management: Factory ECU tuned by Motor City Speed
Output: 626 hp and 628 lb-ft
Built by: Motor City Speed

Drivetrain
Transmission: 6L80 six-speed auto with Yank 3,600-stall converter
Rearend: GM locking diff with 3.42 posi

Chassis
Front suspension: Belltech 2-inch spindles and 2-inch struts
Rear suspension: Belltech 6-inch flip kit, Belltech shocks
Brakes: Stoptech 15-inch rotors and six-piston calipers

Wheels & Tires
Wheels: 22x9.5 Forgeline VR3P
Tires: 305/40R22 Yokohama Parada Spec-X