Engine choices include 4.3-liter V6, 4.8-liter V8, and 5.3-liter V8. The 2500/3500 HD models come with a 300-horsepower, 6.0-liter V8. Five-speed manual and four-speed automatic transmissions are offered.

The new 1500 Crew Cab is powered by the 5.3-liter V8 and features a shorter wheelbase than last year''s 1500 HD (143.5 inches, vs. 153.0), made possible by its extra-short 5-foot-8-inch box. (Last year’s 1500 HD model, with its monster 3094-pound payload, six-passenger Crew Cab, and 6.0-liter V8, has been re-designated a 2500 HD-series model for 2004.)

Base models have been upgraded for 2004 with an attractive chrome grille molding, chrome steel wheels, and a chrome rear bumper, plus cruise control as standard equipment. Carpeting and cloth seats are also standard. The W/T (Work Truck) package is now available on all Sierra models. The W/T deletes the front-end chrome and carpeting, and substitutes vinyl seats, for a credit of $200-$700, depending on cab style.

SLE trim adds a CD player, fog lamps, and a leather-wrapped steering wheel. Leather upholstery is optional. SLT trim, available on Extended Cabs and Crew Cabs, adds automatic air conditioning, a power-adjustable driver’s seat, and OnStar telecommunications.

Sierra Denali, the flagship of the fleet, is an extended-cab, short-bed 4x4. Denali packs a 325-horsepower version of the 6.0-liter V8, along with automatic transmission and an exclusive, sophisticated full-time all-wheel-drive system. Denali comes with OnStar, tone-on-tone leather, dual-zone automatic climate control, extra sound deadening, a Bose audio system with separate controls for rear-seat passengers, a unique console and other exclusive amenities. It''s equipped with steering wheel controls for the audio system, OnStar, trip computer, and other programmable functions. Denali also provides a lockable floor console large enough to hold a picnic lunch for a family of four; it comes with a reversible, removable cup holder tray and a storage nook in front of the lid.

Quadrasteer is available on Sierra 1500 short-bed Extended Cabs and 2500 HD Crew Cabs, and comes standard on the Denali. An electronically controlled four-wheel-steering system, Quadrasteer reduces Sierra’s curb-to-curb turning diameter by 21 percent and enhances high-speed stability. Quadrasteer comes packaged with a limited-slip differential and a trailer-tow package.