Added standard features and the midyear introduction of a light-duty Crew Cab highlight 2004 for GMCs version of GMs full-size pickups. Sierra shares its design with the Chevrolet Silverado. This report covers the half-ton 1500-series models. They offer regular-, extended-, and crew-cab body styles. Extendeds have rear-hinged back doors that dont open independently of the fronts. Crew cabs have four conventional doors. Both include a 3-person rear bench seat. Extendeds and crew cabs offer front bucket seats vs. a bench. Regulars and extendeds are available with conventional 6.6- and 8.0-ft Fleetside cargo beds or a 6.6-ft flare-fender Sportside box.The new half-ton Crew Cab has a shorter bed than the previous 1500 Heavy Duty Crew Cab, which for 04 is redesignated as a 2500-series model. The new 1500 Crew Cab uses a new 5.8-ft cargo box and is virtually the same length overall as the extended-cab short-bed model.Sierra comes in Work, base, SLE, and SLT trim. The flagship Sierra Denali is a luxury/performance e