Engine Block Used Fits John Deere 5101E BCN: R516309U 4 Cyl Diesel BCN: R516309U While we have attempted to list any obvious issues or areas of concern with this particular item, this is not to be considered a comprehensive list. We are not a machine shop and as such, we can only check if a block is cracked, identify any welds or repairs, and notate any patent defects. This is a used, take-out block and may need cleaning and remachining, consult your machine shop/engine builder prior to installation.