Upgrade the charging system on your Duramax for better electrical performance. Suitable as a drop-in replacement for even stock trucks, this heavy duty alternator nearly doubles the factory output, and is also a great upgrade for those stressing their 12 volt system with such add-ons as snow plows, stereo sytems, off road lights, and so forth. Always make sure you've got plenty of juice in the batteries by upgrading with this 220 amp alternator.