When it debuted, the 2007 LBZ improved upon the LLY and the LB7, and was first released prior to increased government regulations which would become a standard for future engines, most notably the exhaust gas recirculation and the diesel particulate filters. For many GMC and Chevy fans, the LBZ would become one of the most sought-after and cherished engines, and, as such, it was no surprise that we chose a LBZ for our next project truck.