Picked up a nice D19 diesel recently overhauled. First time out it overheated and I suspected head gasket. Pulled the head and found that previous owner had indeed overhauled the engine; however, he'd tried to repair a crack between the cylinders and did a very poor job. Took block to a very good machinist who told me the attempt of the previous owner using both very bad welding and epoxy had ruined the block. Haven't found a good "diesel" block yet. However, did find a good running propane engine. Is there any difference in the engines other than the fuel system? Block the same? Head same : if not I can use my current head as it was just rebuilt with new valves, springs and all.