The 2004 Avalanche with the 5.3-liter V8 is rated at 315 horsepower.
In 2004 the Avalanche offered two gasoline V8 options. The most common is the 5.3-liter Vortec 5300 (LM7), which delivers 315 horsepower. A larger 8.1-liter V8 (Vortec 8100) was available on heavier-duty 2500-series models and produces roughly 340 horsepower. The 5.3L was the standard choice for the 1500-series Avalanche, while the 8.1L provided more power for heavier configurations. Exact figures can vary slightly by market and equipment.
Engine options and their horsepower
Below are the factory horsepower figures commonly cited for the 2004 Avalanche’s V8 lineup.
- 5.3L V8 (Vortec 5300 LM7): 315 horsepower
- 8.1L V8 (Vortec 8100): around 340 horsepower
These numbers come from GM’s official specifications for the 2004 model year. The 5.3L was the standard engine for most 1500-series Avalanches, while the 8.1L was used for heavier-duty 2500-series configurations.
Notes on interpretation
Factory horsepower refers to the official ratings at the time of manufacture and can differ slightly from on-road measurements or later re-ratings. For a specific vehicle, the exact figure can vary based on market, emissions equipment, and other options.
Summary
In short, the 2004 Chevrolet Avalanche equipped with the 5.3-liter V8 is rated at 315 horsepower. A second, larger option—the 8.1-liter V8—produces about 340 horsepower for heavier-duty models. These ratings reflect factory specifications from that year and may vary slightly by individual vehicle.