Out of curiosity I started to match up the old engine with the ecm number and the truck vin. Thanks to Cummins Quickserv mobile I've verified the ecm belongs to the truck, and the engine esn should be 57006796.

I bought this truck used, and this engine has never had the valve cover sticker. Finally got around to checking out the block esn by the water pump neck and this is what I found:

Large Font: 2LB003220 5with box around it, then B, then some circle with a line through it vertically

Small font: 3970792

Neither of these match the spec for Dodge Cummins as far as I've researched (8 numbers). Anyone have a clue where this thing is from??