The 2003 Chevrolet Silverado was available in five general trims: Base, LS, LT, SS and Work Truck. Each trim save for the SS had its own sub-trim set -- both the Base and LS had eight, the LT had four and the Work Truck had three. Specifications varied between each trim level, although some remained the same across all trim levels. The 2003 Chevrolet Silverado had 24 trims in all.
The Base 4x2 Regular Cab featured a 4.3-liter V6 engine mated to a five-speed manual transmission with overdrive. It had a three-passenger seating capacity, 119-inch wheelbase and eight inches of ground clearance. The Work Truck 4x2 Regular Cab had the same specifications, save for a 133-inch wheelbase
At the heart of the LS 4x2 Extended Cab was a 5.3-liter V8 engine married to a four-speed automatic transmission with overdrive. It had a six-passenger seating capacity, which was the biggest all 2003 Silverado trims, along with a 157.5-inch wheelbase and eight inches of ground clearance. The LT 4x2 Extended Cab also had these same specifications, except its seating capacity was only limited to five.
The highlights of the SS 4x4 Extended Cab included a 6.0-liter V8 engine, four-speed automatic transmission with overdrive, five-passenger seating capacity, a 143.5-inch wheelbase and eight inches of ground clearance.
In terms of vehicle length, the extended cab variants were the longest at 246.6 inches. The Base trims had the shortest length at 203.2 inches.