tuning taking longer to be EPA certified and placed into production. The second is VIN D. This was introduced in 2006 and continued into 2007 sold only in the "classic" body style. It has an improved engine computer tune that produces increased power and torque over the 2005 LLY version of the engine. First appearance of the Duramax in the Express/Savana vans. The LBZ is one of the more sought after Duramax engines due to its strength, reliability, and being pre-emissions (DPF appeared on the next generation LMM in 2007). Changes include: Cylinder block casting and machining changes strengthen the bottom of the cylinder bores to support increased power and torque Upgraded main bearing material increases durability Revised piston design lowers compression ratio to 16.8:1 from 17.5:1 Piston pin bore diameter increased for increased strength Connecting rod “ I ” section is thicker for increased strength Cylinder heads revised to accommodate lower compression and reduced cylinder firing pressure Maximum injection pressure increased from to more than Fuel delivered via higher-pressure pump, fuel rails, distribution lines and all-new, seven-hole fuel injectors Fuel injectors spray directly onto glow plugs, providing faster, better-quality starts and more complete cold-start combustion for reduced emissions Improved glow plugs heat up faster through an independent controller Revised variable-geometry turbocharger is aerodynamically more efficient to help deliver smooth and immediate response and lower emissions Air induction system re-tuned to enhance quietness EGR has larger cooler to bring more exhaust into the system First application of new, 32-bit E35 controller, which adjusts and compensates for the fuel flow to bolster efficiency and reduce emissions LBZ applications: Chevrolet Silverado HD Chevrolet Kodiak GMC Sierra HD GMC TopKick LLY applications: Chevrolet Silverado HD Chevrolet Kodiak GMC Sierra HD Chevrolet Express full-size (reduced power output mated to a 4L85E transmission) GMC Savana full-size (reduced power output mated to a 4L85E transmission) Specifications Block / Head: Cast gray iron / Cast aluminum Compression: 16.8:1 Injection: Bosch High Pressure Common-rail Power / Torque: LMM The LMM (engine code "6") debuted part way through 2007 and ended production with the start of the 2011 calendar year and is mated to the 6-speed Allison transmission. The LMM was the only Duramax offered for model years 2007–2010. A version was used in the Trident Iceni. Specifications Block / Head: Cast gray iron / Cast aluminum Compression: 16.8:1 Injection: Bosch High Pressure Common Rail with CP3.3 Injection Pump