Trucks in the line at Chevrolet for 2004 go well beyond design expectations with a cab up front for people and a pickup box in back for gear.

Sure, such layouts are available, including the full-size Silverado LD (light-duty) pickup, a larger and stronger variation called Silverado HD (heavy-duty), plus a compact-class truck in the S-10 series or the all-new mid-size model called Colorado. But Chevrolet's truck line offers more, like Avalanche, a unique vehicle cast on Silverado's platform. It has the abbreviated bed of a pickup plus the cabin of a sport-utility wagon with four doors and two rows of seats for fitting up to six.

And there's Chevrolet's crossover idea with the slick SSR, which merges concepts of a pickup and open-top roadster into one high-profile vehicle. Silverado LD trucks in 1500 (half-ton) and medium-duty 2500 (three-quarter-ton) bring options for cabs, beds, powertrains, traction and payloads.

Behemoth Silverado HD trucks, built on a modular structure to allow multiple configurations for cabin size and box length, appear in 2500 (three-quarter-ton) and 3500 (one-ton) packages. Compact-class S-10 trucks now come strictly in four-door Crew Cab configuration.

And Colorado, with dimensions fitting the mid-size segment, is completely new from chassis size to cab designs and truck boxes, with multiple variations and strong new in-line powertrain options.

It's a two-seat roadster and an airy convertible, although with that obvious truck box in back there's no doubt it's also a pickup. Chevrolet calls the unique new vehicle the SSR -- Super Sport Roadster.

Think of it as a cross between a truck and an open-top roadster, but don't expect to see anything else on the road quite like it. There's that bed in back like a truck, but also a retractable hardtop that converts the vehicle via power controls to a breezy convertible. The lid folds in two pieces and tucks vertically behind front seats.

Frame and chassis for SSR were lifted from Chevrolet's mid-size TrailBlazer SUV, and it packs a new aluminum-block version of TrailBlazer's optional V8, a short-block plant displacing 5.3 liters and making 300 hp with GM's 4L60-E Hydra-Matic four-speed transmission.

SSR rolls on alloy wheels clad with performance tires measuring 19 inches up front but 20 inches in back to set up that sporty rump-high stance. (CONTINUED...)