Quote Originally Posted by More Power View Post
The 2001-2004.5 model year Duramax 6600 is an LB7, and the vehicle will have a number 1 (one) as the eighth digit of the VIN. Injectors and injector fuel return lines are beneath the valve covers.

The 2004.5- 2006.5 model year Duramax 6600 is an LLY, and the vehicle will have a number 2 (number two) as the eighth digit of the VIN. Injectors and injector fuel return lines are outside the valve covers.

The 2006.5-2007 model year Duramax 6600 is an LBZ, and the vehicle will have a letter D as the eighth digit of the VIN. The LBZ virtually identical to the earlier LLY, and in-fact, the latest LLY engines are said to be the same as the LBZ, except for power/torque rating, ECM & programming and emissions certification.

The 2007.5 model year Duramax 6600 is an LMM, and the vehicle will have a number 6 (six) as the eighth digit of the VIN. This engine runs with the newest emissions system, which includes a new Diesel Oxidation Catalyst and Diesel Particulate Filter, and requires ULSD (Ultra Low Sulfur Diesel) fuel.

More info and additional details on all of these engines can be found in one of The Diesel Page's content areas (i.e. see the Duramax 6600 Diesel Page to learn more).

Jim
How about the VIN digit for gear ratio? I'm looking into buying a 2006 Duramax LBZ 51,000 miles (would be my 1st desiel if I get it.) Anything I should know MPG, common problems, etc. I'm going to look at it tomorrow afternoon. I will use it to haul a travel trailer 5 or 6 times a year (Approx 7,000 lbs. now and maybe 10,000 lbs. I maybe in the market for a larger camper) Most of my driving will be around town, I drive about 7,000 miles a year avg. Looking for any advise I can get prior to purchase. Thanks in advance.
P.S. Vin# 1GTHK23D86F147471 What can you tell me?