Chevrolet Silverado SS

Personal Trainers For Pickups And Sport/UtesAs recently as three years ago, so-called "tuner" companies were only beginning to improve the performance and appearance of trucks and sport/utility vehicles. Today, it's become a major pastime. The good news is many of the manufacturers of these admired and trusted machines have realized they would like a say in the development and application of the components, and that means, in some cases, warranties are still honored.

We're testing some of the newest models from the top manufacturers: a Shelby SP 360 Dodge Durango, a Roush Stage II supercharged Ford F-150, a 4.6 HSE Callaway by Range Rover, and a concept truck from Chevrolet, the Silverado SS. To add another flavor, we also included a company known for its work with superchargers, Paxton, and its version of a GMC Yukon Denali. Prepare to burn rubber.

We knew this would happen. When Ford announced that a new SVT Lightning performance truck was under development for a mid-'99 introduction, it was inevitable that Chevy would "respond." Ford versus Chevy is a lifelong battle, and one that's often fought harder than the Democrats versus the GOP. Except the Blue Oval Faithful and the Bow Tie Boys do their battling with spec charts and timeslips, as opposed to slogans and rhetoric-though both the politico and the performance enthusiast will resort to a little character assassination whenever possible.

Chevy's "response" is called the Silverado SS, a "what if?" concept truck masterminded by the Silverado brand team and Chevy's Toybox King, Specialty Vehicles Manager Jon Moss. Moss and his minion of in-house and contract hot-rodders started with a standard cab, shortbed version of GM's new pickup, and had at it. The result is a very powerful concept truck that's part Silverado and part Corvette.

The Silverado follows much the same recipe as the upcoming Lightning, with one major exception. While the Ford will employ a supercharger to crank 325-350 horsepower out of its 5.4-liter SOHC Triton V-8, Chevy pursued a more traditional approach for the SS: cubic inches and better breathing.

GM's new 6.0-liter LS1 Vortec V-8 will be offered on 3/4-ton versions of the '99 Silverado and GMC Sierra, and forms the basis for the SS powerplant. Moss and company bolted on a set of ported and polished Corvette aluminum heads, raised the compression ratio from 10.1:1 to 10.5:1, and spec'd out a special roller cam with increased valve lift and longer duration.

The front portion of the exhaust system is made up of OEM manifolds, downpipes, and catalytic converters, while the balance was custom fabricated out of 3.0-inch stainless steel tubing leading to Edelbrock mufflers. K&N provided the open-element air filter system, and the entire engine has been balanced and blueprinted. (How's that for proper hot-rod parlance?)

This dream small-block is good for 395 horsepower and 409 pound-feet of torque, says Chevrolet, and is backed by a beefed up 4L60-E four-speed automatic transmission. Handling is just as important as horsepower with the sport truck crowd, so the SS gets a straightforward but effective suspension redo. Eibach coil springs drop the nose about 1.5 inches, and modified leafs sink the rear some 4.5 inches as compared to a stock Silverado. Stiffer anti-roll bars are used front and rear, and Bilstein provided its best gas-charged shocks.

Every sport truck needs serious rolling stock, and the SS gets that in the form of 18x9.5-inch Billet Specialties wheels, wearing Goodyear Eagle F1 GS 295/45ZR18 tires, quite comparable sizewise to what will show up on the new Lightning. The '99 Silverado is the first full-size domestic pickup to offer four-wheel disc brakes with full-time ABS, and the SS employs the stock system with no modifications.