In 2003, Dodge 5.9L Cummins again met the challenge of producing a 305 hp engine capable of meeting the growing emissions requirements that would also be second to none in power and torque output. Cummins introduced the 325 hp "600" series engine midway through 2004 (identifiable by a red or silver tag on the drivers side of the engine that shows the torque rating at "600"). The "610" model was released in 2005, and was capable of an impressive 325 hp and 610 lb-ft of torque. The 5.9L Cummins 610 remained unchanged through 2006 and the early 2007 5.9L models.