The LBZ is a favorite older Duramax engine. It is simple, and it doesn't have any emission-restricting elements besides the EGR valve. Also, it is using an older and more reliable CP3 Bosch high-pressure fuel pump. Newer Duramax engines made after 2010 are using CP4.2 which is not as nearly good as the CP3. The good sides of this engine are its high power output, and it can handle tuning very well. This engine is the first Duramax to employ stronger, six-speed Allison transmission. That helps in improving fuel economy and offers a comfier ride.