After last year's redesign, the 2004 GMC Sierra 2500HD receives limited changes this year. New is a short bed Crew Cab. The SLE trim gets standard foglights and optional leather seats, and the Work Trucks get cruise control and more chrome around the grille, on the rear bumper, and on the wheels. The 3/4-ton pickup comes in three trims -- Work Truck, SLE, SLT. The Work Truck is only available as a one-row Regular Cab with an 8-foot bed. The SLE and SLE come as either Extended or Crew Cab, seating six in two rows, and with a choice of 6.5-foot or 8-foot pickup beds.

Standard engine is a powerful 6.0-liter, 300-hp V8 with 360 lb-ft of torque. This enables a towing capacity around 10,000 pounds. Other engine choices are an 8.1-liter, 340-hp V8 with 455 lb-ft of torque or the much preferred 6.6-liter turbodiesel Duramax V8 that puts out 300-hp and 520 lb-ft of torque and can tow over 12,000 pounds. Matched with the optional 5-speed automatic Allison transmission, this powertrain is praised by owners of the 2004 Sierra 2500HD. The standard transmission is a 4-speed automatic, but other options are a 5-speed and 6-speed manual. The pickup comes in either rear-wheel or part-time four-wheel drive and rides on 16-inch tires. Standard features are air conditioning, cruise control, ABS brakes, automatic headlights, and dual front airbags. The SLE adds power features and a CD player, and the SLT is equipped with power front seats and leather upholstery. A DVD player is optional for Crew Cabs.

The cargo bed features tie-downs, while a bedliner and cover are extra. In the Crew Cabs, the rear doors open conventionally, while in the Extended, the rear doors are smaller and open in reverse, only in conjunction with the front doors. Overwhelming praise goes to the Duramax/Allison combo as a powerful hauling machine, but owners also like the quiet ride, SUV-style interior comfort and features, and the fuel economy for such a large vehicle. Downsides were a wide turning radius and unknowledgeable dealers.