I have a friend that has a coworker that says that he has a 2004 model lb7 with 350 stock horsepower. In addition to this he says that it hold 21 quarts of oil! Not a misprint, 21 quarts. He said it was a limited build motor and only 4000 were built (seems like quit a few for a limited build), at the beginning of the year. It is in a 3/4 ton crew cab short box. Oh, he also says he gets over 25 mpg stock. I think this is a bunch of bs, am I right? I did some research, and only came up with the lb5 version of the duramax, used in larger trucks.