Chevrolet’s Old Body Style (or OBS) pickup has quickly become a favorite among Bow Tie fans looking for a classic pickup that’s cheap to buy, easy to modify, and comfortable enough to handle the realities of modern driving. Built between 1988 and 1998, the decade-long run of OBS pickups has a following that gets stronger with every passing year.
When Chevrolet decided it was time to replace the OBS with an all-new model at the end of the 1990s, it was facing a tough crowd of established buyers who weren’t interested in the kind of radical changes that brands like Ford and Ram had recently made for their own full-size pickups. Still, Chevy couldn’t fully resist the siren song of that decade’s styling trends, giving the New Body Style truck a distinct personality of its own that created a firm dividing line between the GMT400-platform OBS trucks and the GMT800-platform models that came after it.
In the result—the 1999–2007 Silverado—Chevrolet chose to make the most of the major upgrades under the skin by introducing a legendary series of motors to the truck world.
No More C/K
For three decades, Chevrolet and GMC full-size trucks fell into two categories, indicated by a letter. “C” trucks were two-wheel-drive models, while “K” trucks featured four-wheel drive. This nomenclature dated all the way back to the 1960s, and every pickup produced between then and the late 1990s was referred to as a “C/K” by General Motors.
That all changed when the GMT800 arrived on the scene for the 1999 model year. Chevrolet adopted the Silverado name for all its pickup options, while sister brand GMC went with Sierra. There was no longer any special call-out regarding the vehicle’s driven wheels. Each maintained the standard practice of designating half-ton, three-quarter ton, and full-ton models with the 1500, 2500, and 3500 series numbers, only now those digits followed the pickup’s name rather than using its previous single-letter designation.
From Right Angles to Curvy Muscle
When the Chevrolet Silverado first arrived, it was clear that GM stylists were reacting in part to Ford’s dramatic pivot away from traditional pickup design two years earlier. Although the Silverado’s looks weren’t quite as curvy as those of the recent F-150, they were a departure from the square character of the Old Body Style trucks that had preceded it.
Major changes for the Silverado included a grille that fully wrapped around into the front fenders, with quad-stacked headlights now doing the same, versus the flat front angle presented by the OBS Chevrolet. Later editions of the truck got even more aggressive with the hood and headlight shape, carving out a “cat’s eye” eyebrow that cut in dramatically below the top of the grille. The front bumper was also curved to taper underneath the pickup, housing tow hooks, air vents, and an integrated air dam.
Along the sides of the truck, Chevrolet went all in on available body cladding, offering plastic that clung to the door bottoms, the rockers, and up along the wheelweels to create a mild flare. If you elected to keep the cladding on the shelf, the sheetmetal itself pinched and swelled over each wheel opening to provide a muscular accent. This curvaceous theme continued at the rear of the truck, with a lip at the top of the tailgate (which itself bowed in at the bottom) and taillights whose arch bracketed the back end.
The Silverado also helped launch the trend of ever-larger trucks, checking in wider, taller, and with a longer wheelbase than any of the OBS pickups that had come before
Cabin Quality Takes a Step Up
A big part of those plus-sized proportions had to do with making the Silverado’s interior a more comfortable place to spend some time. This version of the truck finally made it possible for adults to camp out in the second row of extended cab models without enduring the claustrophobic rear quarters offered by the Old Body Style Chevy. A crew cab model that arrived later in the product cycle further improved on things.
The Silverado arrived at the height of GM’s plastic-fantastic interior era, but that didn’t keep the truck’s cabin from registering as a step up over the GMT400 platform. With features like a CD player, power leather seats, and a more comprehensive set of gauges (including an information center that provided additional insight into vehicle status), the Silverado felt modern in a way the OBS simply didn’t—provided you were OK with big knobs and gray molded trim.
Photo: Mecum Auctions
The LS Legend Is Born for Truck Buyers
The single greatest leap forward for the Chevrolet Silverado occurred under the hood. Unlike Ford, General Motors chose to maintain the status quo by using pushrod engines in all its pickups. The Silverado borrowed the same LS V-8 engine architecture that made its debut in the C5 Chevrolet Corvette, and while most examples made use of an iron block rather than aluminum (with aluminum heads sitting on top), it brought forth a long list of improvements and a serious jump in output.
Old Body Style Chevrolets featured a pair of eight-cylinder options in its final two years of production, based on the pre-LS small-block architecture.
5.0-liter
- 230 horsepower / 285 lb-ft of torque
5.7-liter
- 255 horsepower / 300 lb-ft of torque
In contrast, the LS engine family introduced coil-on-plug ignition, better-breathing heads, a larger throttle body, and improved fuel injection, giving it a serious advantage over past efforts. Marketed as the Vortec family of V-8s, two new engine designs were available across the Silverado quarter-ton (1500 series) range in a variety of different tunes.
4.8-liter
- 255 horsepower / 285 lb-ft of torque (1999)
- 270 horsepower / 285 lb-ft of torque (2000-2003)
- 285 horsepower / 295 lb-ft of torque (2004-2007)
5.3-liter
- 270 horsepower / 315 lb-ft of torque (1999)
- 285 horsepower / 325 lb-ft of torque (2000-2003)
- 295 horsepower / 335 lb-ft of torque (2004-2007)
- 310 horsepower / 335 lb-ft of torque (2005-2007)
Starting in 2002, Chevrolet also offered an all-aluminum “high-output” version of the LS engine that could be ordered in top-spec trucks. Originally known as the HO 6000, starting in 2005 it was marketed as the Vortec MAX, with a displacement of 6.0 liters.
6.0-liter Vortec MAX
Chassis Changes Improve Drivability
Nearly as important as the drivetrain upgrades were the improvements that the GMT800 platform provided to the Silverado’s chassis. Although stout, the OBS and its GMT400 platform were a far cry from what modern truck owners would recognize in terms of handling and comfort, especially over rougher pavement.
It started with the frame, divided into three sections that Chevrolet assembled to accommodate varying body style needs and wheelbase lengths. Crucially, the front section of the frame was hydroformed, which added torsional strength that wasn’t available in OBS trucks. Chevrolet also went to 30-spline rear axles across the board with the Silverado 1500 (something that only arrived on later Old Body Style trucks).
In some areas, however, the GMT800 Silverado was one step forward, two steps back. Early models received complaints about ride quality when driven with an empty bed, with the rear leaf springs considered too stiff. Then there were the brakes: From 1999 to 2004, the Silverado was outfitted with four-wheel discs, but after that it reverted to rear drums in a cost-cutting measure.
Quadrasteer Is Ahead of Its Time
Heavy-duty versions of the new Silverado got their own chassis-related party trick for the 2002 model year. Dubbed “Quadrasteer,” the system allowed the rear wheels to move up to 15 degrees out of phase from the front wheels below speeds of 45 mph to make these large pickups more maneuverable. Above 45 mph, the system switched to in-phase, with 5 degrees of angle intended to improve stability.
In addition to dropping the Silverado’s turning radius by 10 feet, Quadrasteer also added over 2,000 pounds of towing capacity to the platform. Unfortunately, its high initial cost repelled buyers, with less than 20 percent of Silverado shoppers ticking that box on the order sheet at its peak. Within three years, it was removed entirely from the GMT800 features list.
The Chevrolet Silverado SS Is Quick but Outclassed
One of the stars of the Old Body Style Chevrolet pickup lineup was the 454 SS muscle truck, which leveraged the brand’s 7.4-liter big-block V-8 alongside monochromatic styling and a handful of suspension upgrades to provide enthusiasts with a little extra oomph. When the Silverado arrived, Chevy wanted to capture some of the same performance truck magic—especially with the Ford SVT F-150 Lightning turning heads among fun-seeking pickup fans.
When it arrived in 2003, the Silverado SS leaned heavily on the blacked-out imagery of its predecessor, with monotube shocks and a suspension drop at all four corners giving it extra visual attitude. Under the hood, it reached out to the Cadillac catalog to borrow the LQ9 6.0-liter LS V-8 that was good for 345 horsepower and 380 lb-ft of torque (before it was known as the Vortec MAX). Initially, four-wheel drive was standard, but it eventually became an option and then, in the final year of production, dropped off the spec list entirely.
These numbers weren’t all that much higher than what could be had from the standard Silverado engine lineup, and it showed when lined up against the regular cab Lightning: The heavy, extended cab Silverado SS was more than a second slower to 60 mph (6.7 seconds). Still, it was quicker than its ancestor (which needed 8.6 seconds to hit the same velocity), and it was much more useful during the winter months thanks to the extra traction it had to offer. The SS model stayed in the mix until 2007.